Computer

The Computer Defined: In basic terms, a computer is an electronic device that process data, converting it into information that is useful to people. Any computer – regardless of its type – is controlled by programmed instructions, which gives a machine a purpose and tell it what to do. What is a Computer System: Computer hardware is composed of CPU, Input/Output devices, Primary & Secondary storage & Communication devices. The input devices accept data and instructions and convert them into a format that the computer can understand. The CPU manipulates the data and controls the task done by other components. The primary storage temporarily stores data and programs instructions during processing. It also stores intermediate results of the processing. The secondary storage stores data and programs for future use. Finally the communication devices provide for the flow of data from external computer networks to the CPU and vise versa. Evolution of Computer Hardware: Computer hardware has evolved through four stages or generations of technology. Each generation has provided increased processing power and storage capacity while simultaneously decreases in cost. Feature 1st (46– 2nd 57-63 3rd (64- 4th (80- 5th 56) 79) 88) 88Circuitry Vacuum Transistors Integrated LSI/VLS ULSI Tubes Circuits I Primary 2 kb 64 kb 4 mb 16mb 64mb Storage Cycle 100 mi 10 mc sec 500 n sec 800 p sec 2000 Time sec p sec Fifth Generation: In this generation massively parallel processing with process of multiple instructions are used in computer. This type of computer use flexibly connected networks linking thousands of inexpensive commonly used chips to address large computing problems attaining super computer speeds. With enough chips networked together a trillion floating point operation per second can be possible. Future Generations: A DNA computation is done by coding a problem into the alphabet and then creating conditions under which DNA molecules are formed that encode all possible solutions of a problem. DNA computer process in parallel are potentially double as fast as today’s super computers. In addition modern storage media stores information at a density 1 bit per 1012 nm while DNA computers have storage density of 1 bit / cubic nm. Optical Computers: Scientist are working on a machine that uses beams of light instead of electrons called optic electronics. These computers are expected to process information several hundred times faster then current computers.

Types of Computer: Computers are distinguished on the basis of their processing capabilities.  Super Computers: The primary activity of super computers had been in scientific and military work but their use is growing rapidly in business as their prices decreases. These are especially valuable for large simulation models, complex mathematical representations and calculations are required for image creation and processing. Super computers uses technology of parallel processing.  Mainframes: This is an ultra high performance computer made for high volume processor intensive computing. It is capable of supporting large data processing, high performance online transaction and extensive data storage and retrieval. Large corporations where data processing is centralized and large databases are maintained most often use mainframe computer. Example of mainframe computer are IBM’s ES000, VAX 8000, and CDC 6600. Mini Computer: This is a small digital computer normally able to process and store less data than a mainframe but more than a micro computer. Mini computer is designed to meet the computing needs for several people which is capable of supporting 4 to 200 simultaneous users. It is a multi user system and used for real time controls and engineering design works. Example: PDP 11, IBM 8000 series and VAX 7500. Micro Computer: This is a small low cost digital computer consist of micro processor storage unit input and output channels all of which may be in 1 chip inserted into one or several PC boards. Originally this was designed for individual users but now days they have become powerful tools for many business that are networked together. E.g. IBM PC Pentium 100, 200, and Apple mackintosh Micro computers includes desktop, laptop and handheld models.

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Computers for Individual Users: Most computers are meant to be used by only one person at a time. Such computers are often shared by several people, but only one user can work with the machine at a given moment. The six primary types of computers in this category are: • Desktop Computers: The most common type of personal computer is the desktop computer designed to sit on a desk or table. Today’s desktop computers are far more powerful than those of just a few years ago, and are used for an amazing array of tasks. Not only do these machines enable people to do their jobs with greater ease and efficiency, but they can be used to communicate, produce music, edit photographs and videos, play games and much more. Used by every one from preschoolers to nuclear physicists, desktop computers are indispensable for learning, work, and play. • Workstations: A workstation is a specialized, single user computer that typically has more power and features than a standard desktop PC. These machines are popular

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among scientists, engineers, and animators who need a system with the power to perform sophisticated tasks. Workstations often have high resolution monitors and accelerated graphics handling capabilities, making them suitable for advanced architectural and engineering design, modeling, animation, and video editing. Notebook Computers: As their name implies, approximate the shape of an 8.5” by 11” notebook. Because people frequently set these devices on their lap, they are also called laptop computers. Notebook computers operate on alternating current or special batteries. Because of their portability they fall into the devices called mobile computers – systems small enough to be carried by their user. Tablet Computers: The tablet PC is the newest development in portable, full-featured computers. Tablet PC offers all the functionality of a notebook PC, but they are lighter and can accept input from a special pen – called a stylus or digital pen that is used to tap or write directly on the screen. Many tablet PC also have a built in microphone and special software’s that accepts inputs from the users voice. A few models even have a fold out keyboards to make it look like a notebook PC. Handheld Computers: These are computing devices small enough to fit in your hand. For e.g. a Personal Digital Assistant (PDA) is no larger than a small appointment book and is normally used for special applications, such as taking notes, displaying telephone numbers and addresses, and keeping tracks of dates and agendas. Many PDAs can be connected to larger computers to exchange data. Most PDAs come with a pen that lets the user to write on the screen and user can access internet through a wireless connection and several models offers features such as cellular telephones, cameras, music players and global positioning systems. Smart Phones: Some cellular phones offers features like web and email access, special softwares like personal organizers, are special hardwares like digital cameras or music players making it different from traditional phones to call it a smart phone.

Stores data and programs. Performs data processing operations Sends results to output unit CPU consists of control unit, ALU, Registers & Primary Storage.  ALU The ALU performs required arithmetic and competitions or logic operations. The ALU adds, subtracts, multiplies, divides compares and determines whether a number is positive, negative or zero. The ALU operations are performed sequentially based on instructions from the control unit. For these operations to be performed the data move from the storage to the arithmetic registers in the ALU.  Control Unit: This unit checks the instructions & directs other components of the computer system to perform the function required by the program. It interprets and carries instructions, contents, in computer, selecting program statements from primary storage, moving them to the instructions registers in the control unit. It controls input and output devices and data transfer processes from and to memory. Memory Unit: This unit holds the intermediate results during the course of calculation and provides the data as and when required. It stores the program instruction and data on which the processor is working. The internal storage section is called primary memory or main memory which stores processed data and intermediary results. When the processing is finished it transfers the final results to an output device.  Registers: The registers are special purpose high speed temporary memory units which holds various information such as data instructions addresses and intermediate results of calculations. Registers are known as CPU’s working memory. Important registers within CPU are Program counters, Instructions Register, Memory Address Registers, Memory Buffer Register, Accumulator and Data Register. Size and length of each register determined by its function and instruction register holds the instructions to be executed and same number of it’s as the instructions.  Buses: set of wires used for interconnection in CPU is known a system bus. System bus has a certain size and width called data path which is measured in bits. It is further divided into three logical units called address bus, data bus and control bus. Input/Output Unit: Computer system incorporates Input & Output devices which acts as a communication medium. Input unit accepts instructions and data from the uses to the computer. Some of the input devices are keyboard, mouse, light pen etc. Output units are instruments of interpretation and communication between human and computer. These devices take the machine coded output results from the processor and converts them into a form that can be used as a machine input in another processing cycle. Monitors, Printers and Plotters are examples.

Computer System (Architecture): Any computer system has three important components. CPU, Input unit and Output Unit. CPU: CPU or the microprocessor is referred as the brain of the computer with VLSI chip inside the system plugged on to the mother board. A processor controls all internal and external devices operates only on binary data composed of 1 or 0 to perform arithmetic and logic operations. Basic functions of CPU are Issues commands to all parts of computer. Controls sequence of operation as per stored instructions,

Database Management System: DBMS is a collection of interrelated data and a set of programs to access those data. The primary goal of a DBMS is to provide a way to store and retrieve database information that is both convenient and efficient. Database systems is a computerized record keeping system which provides mechanisms for the safety of the stored information from data corruption and unauthorized access. DBMS Architecture: The ANSI/SPARC architecture is divided into three levels, known as the internal, conceptual and external level. Internal Level: This is also known as the physical level is the one closest to the physical storage – i.e. it is the one concerned with the way the data is physically stored. External Level: This is also known as the user logical level is the one closest to the users – it is the one concerned with the way the data is seen by individual users. Conceptual Level: This is also known as the community logical level, or sometimes just the logical level, unqualified is a level of indirection between the other two. Working Principle: The DBMS is software that handles all access to the database. Conceptually what happens is the following: • A user issues an access request, using some particular data sublanguage typically SQL) The DBMS intercepts that request and analyzes it. • The DBMS inspects, in turn, the external schema for that user, the corresponding external/conceptual mapping, the conceptual schema, the conceptual/internal mapping, and the storage structure definition. • The DBMS executes the necessary operations on the stored database. Data Models: Underlying the structure of a database is the data model, a collection of conceptual tools for describing data, data relationships, data semantics, and consistency constraints. A data model provides a way to describe the design of a database at the physical, logical and view level. The data models can be classified in four different categories. • Relational Model: The relational model uses a collection of tables to represent both data and the relationships among those data. • Entity Relationship Model: The entity relationship model is based on a perception of a real world that consists of a collection of basic objects called entities and of relationship among these objects. • The object oriented data model is another data model, which can be seen as an extension of E-R model with notations of encapsulation, methods, and object identity. The object relational data model combines features object oriented data models and relational model. • Semi structured Data Model: The semi structured data model permits the specification of data where individual data items of same type may have different set of attributes. The Extended Markup Language (XML) is widely used to represent semi structured data. Historically, the network model and the hierarchical model precede the relational model. These models are tied closely to the underlying implementation, and complicated the task of modeling data. As a result they are used little now, except in old database code that is still in service in some places. Database Languages:

A database system provides a data-definition language to specify the database schema and a data-manipulation language to express database queries and updates. In practice, the data definition and data manipulation languages are not separate languages, instead they simply form parts of a single language, such as the widely used SQL language. Database Design: Database systems are designed to manage large bodies of information. Database design mainly involves the design of database schema. The design of a complete database application environment that meets the needs of the enterprise being modeled requires attention to a broader set of issues. Benefits of Database Systems: Database systems arose in response to early methods of computerized management of commercial data. The typical file processing systems is supported by conventional operating system. Using the database approach has the following benefits over the traditional file processing approach.  Data Redundancy: This refers to duplication of data. In non database system each application with own separate files often lead to redundancy in store data which results in wastage of space. Database systems does not maintain separate copies of the same data. All the data kept in one place and various applications refer from this centrally controlled system.  Data Inconsistency: Database is said to be inconsistent when contradictory information will be supplied to the users. DBMS ensures the database is always consistent by ensuring that any change made to either of the two or more entities is automatically applied to the other one also. This process is also known as propagating update.  Sharing of Data: Sharing of data allows the existing application to use the data by multiple users of the database system. Due to shared data it is possible to satisfy the data requirement of new applications without creation of additional stored data or marginal modification.  Enforcement of Standards: DBMS uses standard measures in naming, formatting and structuring while creating and using data within the organization. This ensures easier enforcement of data usage particularly in migrating and interpreting data between two different systems.  Data Security: To ensure security DBMS provides security tools such as user codes and passwords so that data security checks can be carried out whenever access is attempted to sensitive data.  Concurrent Access: For the sake of overall performance and faster response time many systems uses multiple users to update the data simultaneously. In such environment interactions of concurrent updates may result in data inconsistency. DBMS guards against this possibility by maintaining some form of supervision into such applications.  Atomicity Problems: A computer system like any other mechanical device is subject to failure. In many applications it is crucial that if a failure occurs the data is restored to the consistent state that existed prior to the failure. DBMS takes care of such problems by making the transactions atomic – it must happen in entirety or not at all.  Data Integrity: Data integrity refers to ensuring data in database is accurate. This is ensured through enforcing various integrity constraints during the time of creation of data structure.  Better Interaction with Users: In case of DBMS the availability of up-to-date information improves and makes it easy to respond to unforeseen information request. Centralizing the data in database allows users to obtain new and combined information. Efficient System: in DBMS the contents of stored data can be changed easily and do not have any impact on the application programs. Initial cost of DBMS may be high but overall costs is less compared to conventional system.

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Systems Vulnerability (Computer Security & Crime): Information systems are made up of many components that may be in several locations. Thus, each information system is vulnerable to many potential hazards. The vulnerability of information system is increasing as we move to a world of networked computing. Theoretically, there are hundreds of points in a corporate information system that can be subject some threat. These threats can be classified as unintentional or intentional. Unintentional Threats: These are divided into three major categories – human errors, environmental hazards and computer system failures • Human Error: Errors can occur in the design of the hardware and/or information systems. They can also occur in the programming, testing, data collection, data entry, authorization, and instructions. Human errors contribute to the vast majority control – and security related problems in many organizations. • Environmental Hazards: This includes earthquakes, hurricanes, severe snow, sand storms, floods, tornadoes, power failures or strong fluctuations, fires, defective air conditioning, explosives, radio active fallout and water cooling system failures. • Computer System Failures: This can be result of poor manufacturing of defective materials. Unintentional malfunction can happen for other reasons ranging from lack of experience to incompatibility of software. Intentional Threats: Computer system may be damaged as a result of intentional actions. Here are some examples. Theft of Data Inappropriate use of data Theft of mainframe computer crime Theft of equipment and/or programs • Deliberate manipulation in handling, entering, processing, transferring or programming data. • Labor strikes, riots or sabotage. • Malicious damage to computer resources • Destruction from viruses and similar attacks. • Miscellaneous computer abuses and crimes. Computer Crimes: According to CSI 64% of all corporations experienced computer crimes in 1997. The number, magnitude and diversity of computer crimes and abuse are increasing rapidly. Lately increased fraud related to the Internet and electronic commerce is in evidence. Types of Computer Crimes In many ways, computer crimes resemble conventional crimes. They can occur in four ways. • First, the computer can be target of the crime. For e.g. a computer may be stolen or destroyed or virus may destroy data. • Second, the computer can be the medium of the attack by creating an environment in which a crime or fraud can occur. For e.g. false data are entered into computer system to mislead individuals. • Third, the computer can be the tool by which a crime is perpetrated. • Forth, the computer can be used to intimidate or deceive. For instance, a stock broker stole $50 million by convincing his clients that he had a computer program with which he could increase their return on investment by 60% per month. Computer Criminals: Crimes can be performed by outsiders who penetrate a computer system frequently via communication lines or by insiders who are authorized to use the computer system but are misusing their authorizations. • Hacker: is the term often used to describe outside people who penetrate a computer system.

• A cracker is a malicious hacker who may represent a serious problem for a corporation. Methods of Attack: Two basic approaches are used in deliberate attacks on computer systems: data tampering and programming techniques. • Data Tampering (Data Diddling): This is the most common approach and is often used by the insiders. It refers to entering, false, fabricated data into the computer or changing or deleting existing data. • Programming Techniques: Computer criminals also use programming techniques to modify a computer program, either directly or indirectly. For this crime, programming skills and knowledge of the targeted systems are essential. • Viruses: The most common publicized attack method, the virus receives its name from the programs ability to attach itself to other computer programs causing them to become virus themselves. A virus can spread throughout a computer system very quickly. Due to the availability of public domain software, widely used telecommunications network, and the Internet, viruses can also spread too many organizations. Viruses are known to spread all over the world. Some of the most notorious viruses are “International”, such as Michelangelo, Pakistani Brain, and Jerusalem. When a virus is attached to a legitimate software program, the program becomes infected without the owner of program being aware of the infection. Therefore, when the software is used, the virus spreads, causing damage to that program and possibly to others. Thus, the legitimate software is acting as a Trojan horse. Security Challenges: Knowing about major potential threats to information systems is important, but understanding ways to defend against these threats is equally critical. Defending information systems is not a simple or inexpensive task for the following reasons. • Hundreds of potential threats exist • Computing resources may be situated in many locations. • Many individuals control information assets. • Computer networks can be outside the organization and difficult to protect • Rapid technological changes make some controls obsolete as soon as they are installed. • Many computer crimes are undetected for a long period of time so it is difficult to learn from experiences. • People tend to violate security procedures because the procedures are inconvenient. • Many computer criminals that are caught go unpunished, so there is no deterrent effect. • The amount of computer knowledge necessary to commit computer crime is minimal and one can learn hacking for free in the internet. • The cost of preventing hazards can be very high. Therefore most organizations simply cannot afford to protect against most possible hazards. • It is difficult to conduct a cost benefit justification for controls since it is difficult to assess the value of hypothetical attacks. Protecting Information Systems: Protection of IT is accomplished by inserting controls – defense mechanisms – intended to prevent accidental hazards, deter intentional acts, detect problems as early as possible, and enhance damage recovery and correct problems. Controls can be integrated into hardware and software during the software development phase. They can also be implemented once the system is in operation or during its maintenance. The important point is that defense should stress prevention; it does no good after the crime. Since there are many threats, there are many defense mechanisms. Defense Strategies: The selection of a specific strategy depends on the objectives of the defense and on the perceived cost benefit.

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Controls for Prevention: Properly designed controls may prevent errors from occurring, deter criminals from attacking the system, and better yet, deny access to understand people. Detection: It may not be economically feasible to prevent all hazards and deterring measures may not work. Therefore, unprotected systems are vulnerable to attacks. Like a fire the earlier it is detected the better it is to combat. Limitation: This means to minimize losses once a malfunction has occurred. This can be accomplished by including a fault tolerant system that permits operations in a degraded mode until full recovery is made. Recovery: A recovery plan explains how to fix damaged information systems as quickly as possible. Replacing rather than repairing components is one route to fast recovery. Correction: Correcting damaged systems can prevent the problem from occurring again. Information System Controls: They can be divided into two major categories – general system controls and application controls. General Controls: These are used to protect the systems regardless of specific applications. The major categories of general controls are physical controls, access controls, data security controls, communication controls and administrative controls. Physical Controls: Appropriate physical security may include several controls such as the following: Appropriate design of data center. Shielding against electromagnetic fields. • Good fire prevention, detection and extinguishing system, including sprinkler system, water pumps, and adequate drainage facilities. A better solution is fire-enveloping system. • Emergency power shutoff and backup batteries, which must be maintained in operational condition. • Properly designed, maintained and operated air conditioning system. • Motion detector alarms to detect physical intrusion. Access control Access control is the restriction of unauthorized user access to a portion of a computer system or to the entire system. To gain access, a user must be authorized. Then when the user attempts to gain access he or she must be authenticated. Access procedures match every valid user with a unique user identifier. They also provide an authentication method to verify that users requesting access to the computer system really who they claim to be. User identification can be accomplished when the following identifies each user. Something only the user knows such as a password Something only the user has such as a smartcard • Something only the user is such as signature, voice, fingerprint, or retinal scan, iris scan, DNA code implemented via biometric control Data Security Controls: Data security is concerned with protecting data from the accidental disclosure to unauthorized persons or from unauthorized modification or destruction. Data security functions are implemented through operating systems, security access control programs, database or data communication products recommended backup/recovery procedures, application programs and external control procedures. Data security must address the issues like confidentiality of data, access control, and critical nature of data and integrity of data. Communication/Network Controls: Network is becoming extremely important as the use of internet/intranet and ecommerce increases. • Encryption: Encryption encodes regular digitized text into unreadable scrambled text or numbers to be decoded upon receipt. Encryption accomplishes three purposes. 1. Identification: (helps identify legitimate senders and receivers) 2. Control: (prevents changing a transaction or message) and 3. Privacy (impedes eavesdropping).

A widely accepted encryption algorithm is Data Encryption Standard (DES), produced by the US National Bureau of Standards. Many software products are available for encryption. Traffic padding can further enhance encryption. Here a computer generates random data that are intermingled with real data making it virtually impossible for an intruder to identify true data. To ensure secure transactions of the internet, Revising and VISA developed encrypted digital certification systems for credit cards that allows customers to make purchases on the internet. Credit card holders create a digital version of their credit card, Revising confirms validity of the buyer’s credit card, and then it issues a certificate to that effect – even the merchants do not see the credit card number. Firewalls: A firewall is a system or a group of systems that enforces an access control policy between two networks. It is commonly used as a barrier between the secure corporate intranet or other internal networks and the internet which is assumed to be unsecured. Firewalls are used to implement control access policies. The firewalls follows strict guidelines that either permits or blocks traffic, therefore, a successful firewall is designed with clear and specific rules about what can pass through. Several firewalls may exist in one information system. Administrative Controls: Administrative controls deal with issuing guidelines and monitoring compliance with the guidelines. Representative examples of such controls include the following: Appropriately selecting, training and supervising people Fostering company loyalty • Immediately revoking access privileges of dismissed, resigned or transferred employees. • Requiring periodic modification of access controls • Developing programming and documentation standards • Instituting separation of duties • Holding periodic & random audits of the system.

E-COMMERCE : Electronic commerce (also referred to as EC, e-commerce or ecommerce) consists primarily of the distributing, buying, selling, marketing, and servicing of products or services over electronic systems such as the Internet and other computer networks. The information technology industry might see it as an electronic business application aimed at commercial transactions; in this context, it can involve electronic funds transfer, supply chain management, emarketing, online marketing, online transaction processing, electronic data interchange (EDI), automated inventory management systems, and automated data collection systems. Electronic commerce typically uses electronic communications technology of the World Wide Web, at some point in the transaction's lifecycle, although of course electronic commerce frequently depends on computer technologies other than the World Wide Web, such as databases, and e-mail, and on other non-computer technologies, such as transportation for physical goods sold via e-commerce History: Electronic commerce applications began in the early 70s with such innovations as electronic transfer of funds. However, the applications were limited to large corporations. Then came EDI, which expand EC from financial transactions to other kinds of transaction processing and extend the types of participating companies from financial institutions to manufacturers, retailers, services and other forms of business. With the commercialization of the Internet making available 60 million potential customers, EC applications have expanded rapidly. Over the last five years we have witnessed many innovative applications from advertisement to auctions and virtual reality experiences. The EC Area: The EC applications are supported by infrastructure (five categories) and the implementation of these applications depends on four major areas: people, public policy, technical standards and protocols, and other organizations. The EC management coordinates the applications, infrastructures and pillars. Another way to look at the EC field is to divide it into the following two components:  Interorganisational Information Systems (IOS): IOS involves information flow among two or more organizations. Its major objective is efficient transaction processing, such as transmitting orders, bills, and payments using EDI. All relationship are predefined, there is no negotiation, just execution. Interorganisational systems are used exclusively for b2b applications. Benefits and Limitations of e-Commerce: Few innovations in human history encompass as many benefits as electronic commerce. The global nature of the technology, the low cost, the opportunity to reach hundreds of millions of people, the interactive nature, the variety of interaction possibilities, and the resourcefulness and rapid growth of the supporting infrastructure, especially the Internet, result in many benefits to organizations, individuals and society etc. the benefits are just starting to materialize, but they will increase significantly as EC expands. Benefits to Organizations: EC expands the market place to national and international markets. With minimal capital outlay, a company can easily and quickly locate more customers, the best suppliers and the most suitable business partners worldwide.  EC decreases the cost of creating, processing, distributing, storing and retrieving paper based information.  EC allows reduced inventories and overheads by facilitating pull type supply chain management where the process starts from customer orders and uses just in time processing. This allows product customization and lowers inventory costs.  EC reduce the time between the outlay of capital and the receipt of products and services.  EC supports BPR efforts. When processes are changed, productivity of salespeople, knowledge workers, and administrators can increase by 100% or more.  EC lowers telecommunications cost; the Internet is much cheaper than VANs.  EC helps small businesses to compete against large companies.

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EC enables organizations to reach customers outside their immediate area at a minimum cost. EC allows organizations to reach a wide range of suppliers, thereby reducing the cost of suppliers can share benefits. EC allows companies to auction surpluses or obsolete products quickly with little expenses. EC facilitates global trade, allowing companies to penetrate foreign markets.

Benefits to Customers:  EC provides customers with more choice; they can select from many vendors and from more products.  EC frequently provides customers with less expensive products and services by allowing them to shop in many places and perform quick comparisons.  In some cases EC allows quick delivery of products and services.  Customers can get relevant and detailed information in seconds.  EC makes it possible to participate in virtual auctions.  EC allows customers to interact with other companies in electronic communities and to exchange ideas and experiences. Technical Limitations:  Lack of system security, reliability and standards and communication protocols.  Insufficient telecommunications bandwidth  The s/w development tolls are still evolving and changing rapidly.  Difficult in integrating the Internet and EC s/w with some existing applications and databases.  The need for special Web servers in additions to network servers.  Classification of eCommerce: B2B eCommerce: Business-to-Business Electronic Commerce, also known as E-Business, is experiencing an explosive growth rate on the Internet. Companies of all sizes and types are now mutually buying and selling products and services on the Internet. B2B also offers unique benefits such as less human intervention, less overhead expenses, fewer inadvertent errors, more efficiency, more advertising exposure, new markets and new physical territories equate to an intelligent method of mutual business. It is a win-win situation for both buyer and seller. These are just a few of the benefits that B2B E-commerce can offer. It is already well accepted in the business community, that the potential return of doing business on the Internet is far greater than the investment. The bottom line is greater profits for the business. Currently there are 2 main issues to deal with when conducting a B2B E-commerce  Supply Chain Management - to co-ordinate the fields of competition turned to efficiency in manufacturing. In the 80's, concepts like Lean Manufacturing, Design for Manufacturability, Just-in-Time, and Stockless Production emerged. If properly managed, the operating costs of such systems can be substantially reduced. Reduction in costs can be in the form of reduced inventory cost, obsolescence, transportation and other logistics costs, overhead and direct labor costs. All have pointed out potential savings in costs that could amount to billions when companies can engage in supply chain integration efforts.  Electronic Procurement System - using Internet technologies to handle product distribution to the buyer and from supplier while at the same time removing the complexity of multi-level paper and processing which are labors intensive. This allows the business to run more efficiently and allows purchasing professionals to have more time to focus on complex acquisitions and supplier negotiation. Besides reducing cost and hassle, it must be

designed expressly for casual use by untrained employees and it must also provide extensive management controls, reporting, and integration with existing systems. B2C e-Commerce: B2C (Business-to-Consumer) is basically a concept of online marketing and distributing of products and services over the Internet. It is a natural progression for many retailers or marketer who sells directly to the consumer. The general idea is, if you could reach more customers, service them better, and make more sales while spending less to do it that would the formula of success for implementing a B2C e-commerce infrastructure. For the consumer, it is relatively easy to appreciate The importance of e-commerce: Why waste time fighting the very real crowds in supermarkets, when, from the comfort of home, one can shop on-line at any time in virtual Internet shopping malls, and have the goods delivered home directly. Who should use B2C e-Commerce?  Manufacturers - to sell and to retail the business buyers  Distributors - to take orders from the merchants they supply  Publisher - to sell subscriptions and books  Direct Sales Firms - as another channel to reach the buyers  Entertainment Firms - to promote new products and sell copies  Information Provider - to take payment for downloaded materials  Specialty Retailers - Niche marketers of products ranging from candles, coffees, specialty foods, books use it to broaden their customer reach.  Insurance Firms - On-line rate quotes and premium payments have made it easier for this industry to attract and retain customers. In fact, virtually any business that can deliver its products or provide its services outside its doors is a potential user C2C e-Commerce: It is sometimes referred to Peer2Peer (P2P) exchanges involve all transactions between and among consumers. These transactions can also include third party involvement, usually in the form of those who facilitate the marketplace such as EBay.com. C2C exchanges can include classified ads (the Trading Post online), music and file sharing, career and job websites (Seek and CareerOne) and also personal services such as dating websites (Lavalife). In C2C networks, consumers sell goods and services to other consumers. There are millions of sellers with different items to sell and an equally large number of buyers. Finding each other can incur quite a high cost to both buyer and seller, and thus this is why intermediaries like eBay are so important. They simply mediate between consumers who want to buy and sell, and take small cuts of the sellers profit as a fee for bringing their customers to one marketplace. Consumer2Consumer e-commerce has given online shopping and trading a new dimension. While this sort of trading is prevalent in the offline world (garage sales, etc) it was not expected to take off so well online, due to the anonymity of users. The advantage of consumer to consumer e-commerce is most often the reduced costs and smaller but profitable customer base. It also gives many small business owners a way to sell their goods without sinesses involve items such as handmade gifts, personal artwork, clothing, running a highly profit draining bricks-and-mortar store. Uses of E-Commerce:  Advertising, Online Publishing and Push Technology:

Advertisement and dismissing of products or service information are currently the largest commercial activities on the internet. This is generally conducted through organization’s owns website, other organizations web site electronic publishers web site electronic commerce vendors pages information kiosks electronic malls news groups and other innovative approaches.  Banking, Personal Finance and Stock Trading: Electronic banking also known as cyber banking, virtual banking, home banking and online banking includes various banking activities conducted from home, business, or on the road instead of a physical bank location. It has capabilities ranging from paying bills to securing a loan electronically saves time and money for users.

Internet Concepts: With the growing popularity of computers and subsequent networking abilities inter communication between diff. computers became easier and led to the phenomenon called internet. Derived from two words ”interconnection and networks”, internet is a world wide system of computer networks i.e. a network of networks. It allows the participants to share information on those millions of linked computers. This high level of connectivity gives rise to an unparalleled degree of communication, resource sharing and information access. Evolution of internet The origin of internet dates back to 1960s and is the result of an experiment conducted by the US department of defense. In 1969 a 4 computer network called Arpanet was designed for communication of the US defense scientist. By 1970 ARPA (advanced research projects agency) developed a new protocol named as TCP/IP (transmission control protocol/ internet protocol) for transferring data between networks. In 1980s National Science Foundation (NSF) used Arpanet to link super computers at measure universities for sharing wok. The rapid growth of the Internet was due to networking giants like British Telecom, Hyundai, AT&T and others setting up fast and reliable networks that encircled the globe. These networking giants gave access to the internet via gateways Using ISP gateway it is perfectly possible to route business or commerce data from one point of globe to another. An ISP gateway generally consist an ISP server to the internet called its internet pipeline. ISP pipeline bandwidth of 2 to 10 GB is quite common. Clients that log into Internet via ISP commonly use only 33.6 kilobytes of ISP’s bandwidth. Occasionally a client whose data traffic is very high will use special connectivity methods (ISDN) to an ISP server and use 64kbps to 128kbps of ISP bandwidth. MNC’s directly negotiate with networking giants to have their own private gateway and then make use of huge bandwidth for its data transfers. However modern day internet became popular in the 1990s after the development of World Wide Web (WWW) by European research organization (CERN). The CERN developed the protocol based on hyper text (HTTP) for connecting to content using hyper link. The WWW also permitted access to information using a Graphical User Interface (GUI). Working of internet TCP/IP is the only protocol used to send data on the internet. It is the combination of two individual sections – TCP, a set of communication protocols and IP, a unique address. Every machine connected to internet most have an unique IP address assigned by the Internet Service Provider (ISP) to identify that machine. This unique IP address therefore points to an actual computer known as ‘domain’ which is connected via a gateway to the internet. A physical domain (server) having a permanent IP address can provide –  Gateway to other computers, Information for internet users to read,  A physical location on which several virtual domains can be hosted known as ‘websites’ e.g. www.microsoft.com Virtual domains are identified by a name (e.g. www.microsoft.com). Virtual domain names needs to be unique on the Internet. All virtual domain names must be registered with InterNIC. Virtual domains can be conceptualized as subdirectories on an internet server’s hard disk. The information that internet clients wish to read would be ‘Files’ within the subdirectory. When an Internet client requests for connection to a virtual domain on the internet, the request is routed to the proper Internet Server using TCP/IP. The Web Server running on this Internet Server then handles the request, resolves the Virtual Domain Name sent along with this request, to an appropriate subdirectory on the Internet Server where the website is hosted. Computers that only read information offered need not have a permanent IP address. However when logged into internet a client requires a unique IP address. This IP address enables the Internet server called, to reply accurately. The ISP server via which the client connects to the Internet temporarily assigns a unique IP address to the client. ISP’s purchase a block of unique IP address from internationally recognized networking bodies. Thus whenever a client logs on, via the ISP’s server one of the unique IP address is temporarily assigned to the computer. The maximum number of computer that can log into an ISP server is therefore limited to the blocks of unique IP address purchased by the ISP from the international body. Resolving Domain Names:

When any client wishes to communicate with any internet server, using a web browser, the client sends out a broadcast using the Servers Domain name as its identifier.  The ISP Internet Server intercepts this request first.  Should the ‘Domain Name’ be unknown to the ISP’s Internet Server.  The ISP Internet Server will broadcast to an InterNIC Root Server.  In the InterNIC Root Server’s Hosts file the Domain Name will be mapped to an IP address.  This IP address will be returned to the ISP’s server.  The ISP’s server will now pass this IP address back to the client browser.  The Client browser will now broadcast a request to connect directly to the Internet Server using its IP address.  As soon as this call is heard by the Internet Server it will respond and a link is established between the client and the Internet Server.  Web Server software running on the Internet Server takes care of connecting a client to the virtual domain as required.  Once the client is connected to the appropriate domain, the Web Server Software delivers the client the first HTML page of that domain and browsing for the specific domain can begin. The TCP/IP: TCP/IP uses IP to deliver packets to the upper layer applications and provides a reliable stream of data among computers on the network. Once the packets arrives at the correct IP address, TCP goes to work. TCP main task is error checking, to make sure that the right number of packets are received and they are in proper order. Thus TCP guarantees that the information that was received by a computer on TCP/IP network, is exactly the same information that was sent to by another computer in the network. The IP is responsible for basic network connectivity when mapped to the TCP/IP layers, the IP works with the ‘Network Layer’ in networking there has to be a physical location to send data to or receive data from. To make this happen every physical location must have a unique network address. Hence every computer on a TCP/IP network must have an IP address, which is unique to that computer. The IP address is a set of numbers separated by periods. An IP address is a 32 bit number, divided into two sections, the network number and the host number. Address are written as four fields, eight bits each separated by a period. Each field can be a number ranging from 0 to 255. this method of addressing is called dotted decimal notation. TCP/IP consists of protocols, applications, and services. Protocols enable a server application to offer services, and a client application to use these services Getting Connected The basic requirements for online are 1. A TCP/IP enabled computer with a browser 2. An account with an ISP 3. A telephone line or WAP 4. Modem to connect the computer to the telephone line. Types of Internet Connections Common types of internet access available for the users depending on the requirements are 1. ISDN (Integrated services digital network) 2. Cable modem 3. Leased lines of very high connectivity 4. Digital subscribed line (BSNL broad band) 5. Satellite broadband 6. Dial up connection. Internet Services:

Due to the colossal growth of internet the user has access to a wide verity of services available on the net. 1. World Wide Web (www): It is a subset of internet and presents a wide variety of information in the form of text, images, animation, video, sound and multimedia on a single interface. 2. Email: it is the most used application on the net. Each user of email has a mailbox address to which messages are sent and the mailbox can be accessed from any where, any time. 3. File transfer protocol (FTP): Software programmed that enables user to log on to another computer and transfer information. 4. Telnet: derived from telecommunications and network. This protocol allows the user to log on to a remote computer any where in the world and use it as if it is available locally. 5. Internet relay chat (IRC): IRC is a service that allows communicating in real time and carrying on conversations via the computer with one or more people. 6. Instant messaging: Communication in real time by typing text, also used for sending Sass 7. Internet Telephony: Use of internet to exchange spoken or telephonic information bypassing traditional telephone infrastructure. 8. Video conference: Same technology as IRC but provide sound and video. A VC system has two or more parties in different location using a combination of video, audio and data. 9. E-commerce: Conducting business on the internet. This refers to buying and selling of goods and services online. Concepts of B2B, B2C, C2C, Internet banking etc… e..g. www.amazon.com, www.ebay.com. 10. News groups: International discussion groups that focus on particular topic and help in gathering information about that topic. 11. Mailing list: The internet is a home to a large community of individuals organized around topic oriented forums. To carry out active discussions distributed via email. 12. Search engines: Searching the wealth of information on just about any topic using special tools called search engines e.g. www.google.com.

OPERATING SYSTEM: An operating system is a collection of system programs that together control the operations of a computer. OS along with h/w, application and other system s/w and users constitute a computer system. An OS has 2 objectives:  To manage the computers h/w  To provide an interactive interface to the user and interpret commands for communication with the h/w. The OS receives the users input from the keyboard or other input device and then outputs the data to the monitor or other such output devices. It also handles an error handling device and displays an error notification. The OS organizes applications so that users can easily access, use and store them. A major part of the applications interface is based on the OS. If a program is not functioning properly the OS takes control, stops the application and displays appropriate error message. TYPES OF OPERATING SYSTEMS: The different types of OS can be classified into six broad categories: o Batch processing OS: This was the first to evolve and allowed only one program to run at a time. Still in use in many of the mainframe computers. o Time Sharing or Multi User OS: Used in computer networks which allows different users to access the same data and application programs on the same network o Multi Tasking OS: In this kind of OS more than one process (tasks) can be executed concurrently. The processor is switched rapidly between the processes. This allows a user to switch between the applications and even transfer data between them. o Real Time OS: RTOS are designed to respond to an event within a predetermined time. This is primarily used in process control, telecommunications etc. RTOS responds quickly, hence they are often used in Railway and Flight reservation systems. o Multi-processor OS: This can incorporate more than one processor dedicated to running processes. This technique is often called Parallel Processing. o Embedded OS: Refers to the OS that is self contained in the device and resident in the ROM. These embedded systems are usually not general purpose. Typical systems include car management systems, household appliances, traffic control systems etc.

FUNCTIONS: The main functions of a modern OS are:  Process Management: As a process manager the OS handles the creation and deletion, suspension and resumption, scheduling and synchronization of processes. A process is an execution of sequence of instructions or programs by the CPU. The various states that the process changes during execution are: New, Ready, Running, Waiting and Terminated. A Thread is a task that runs concurrently with other tasks within the same process, also known as lightweight process. A single thread of control allows the process to perform only one task at a time. In a Multitasking operating system a process may contain several threads, all running at the same time within the same process. Writing a program with multiple threads is called Multitasking Programming. Uni-programming implies only one process at a time whereas in a multiprogramming system multiple processes can be initiated at the same time. The OS ensures that all the programs get their fair share of CPU time and get to share other resources. The OS also allocates processor time to all the ready processes, referred to as scheduling. The different levels of scheduling are High, Medium and Low levels. Popular scheduling procedures implemented by different OS are o ‘First Come First Serve’ or ‘First in First out’ o ‘Round Robin Scheduling’. FIFO involves a procedure in which processes enter the queue and access the processor in a sequential manner. In Round Robin scheduling a process is selected for running from the ready queue but must only run for fixed period after which it will be interrupted and returned to the end of the ready queue. In this the processes are allocated CPU time on a turn basis. In a multiprogramming environment a process may have to wait endlessly because the requesting resource may be held by other waiting resources. This type of a situation is known as Deadlock. A deadlock situation arises if the following 4 conditions hold simultaneously on the system. o Mutual Exclusion: Only one process can use a resource at a time. If an additional process is there it has to wait till the requested resource is released.

o Hold and Wait: A process might be holding some resource while waiting for another resource. o No Preemption: A resource can only be released voluntarily by the holding process and cannot be forcibly removed. o Circular Wait: A situation whereby processes P1 and P2 exist in such a way that P1 is waiting for a resource held y P2 and vice versa. To ensure that a deadlock never occurs, OS uses a deadlock prevention or deadlock avoidance scheme. Memory Management: OS also manages the primary memory of the computer and that part of the computer is called Memory Manager. Managing the primary memory, sharing and minimizing memory access time are the basic goals of the memory manager. The major tasks performed by the memory manager are: o Relocation: Each process must have enough memory to execute. This is done thru swapping between 2 processes to free up memory space. o Protection and Sharing: A process should not run into another process’s memory space. This is achieved thru proper memory allocation and the different strategies used for this are best fit, first fit and worst fit. Concept of Virtual Memory: Virtual memory in other words is a way of making the real memory of a computer system effectively larger than it actually is. The system does this by determining which parts of its memory are often sitting idle, and then makes a command decision to empty their contents onto a disk, thereby freeing up precious RAM. File Management: The file manager is responsible for the maintenance of the file system which contains a hierarchical structure of data. This system contains both user data and meta data (data describing the files of user data). The file system usually contains metadata in the form of directories and sub-directories. The file manager also provides a logical way to organize files in the secondary storage. The sequential address of directories within directories is called the directory path. Device Management: This involves the process of managing various devices connected to the computer. The device manager manages the h/w resources and provides an interface for application programs. The OS communicates with the h/w thru standard s/w provided by the h/w vendor called device drivers. Device driver works as a translator between the electrical signals from the h/w and application programs of the OS.

Spooling: SPOOL is an acronym for Simultaneous Peripheral Operation On-line. This refers to storing jobs in a buffer from where a device can access them when it is ready. Security Management: This involves protecting information residing in the system from unauthorized access. Various security techniques employed by the OS to secure the information are user authentication (password protection) and back-up of data. User Interface: The OS has the responsibility of providing access to the h/w for whatever the application needs. When an application is opened the OS lets the application provide the majority of the user interface. Common interfaces provided by different Operating Systems can be categorized as Command Line Interface (CLI) and Graphical User Interface (GUI). CLI is based solely on textual input whereas GUI offers a variety of graphical elements onscreen.

Data Communication System: A communication system is defined as the collection of software and hardware that facilitates inter system exchange of information between different devices. Sharing of info is of 2 types. 1. Local (face to face communication) 2. Remote (Communication over distance). The fundamental characteristics of data communication is considered as follows. 1. Delivery ( The system must delver data to the correct destination 2. Accuracy ( The system must deliver data accurately 3. Timeliness ( System must deliver data in a timely manner without enough time lags Data Communication. Components. 1. Message: It is the info. That is to be communicated 2. Sender: I is the device that sends the message 3. Receiver: Device that receives the message 4. Medium: The transmission medium is the physical path that communicates the message from sender to receiver. 5. Protocol: Protocol refers to a set of rules that coordinates the exchange of info. Both the sender and receiver should follow the same protocol to communicate data. Data Transmission Mode: 1. Simplex mode: It is unidirectional. The info flows in one direction across the circuit with no capability to support response in the other direction. E.g. TV transmission 2. Half Duplex: In this mode each communication device can receive and transmit info but not at the same time. When one device is sending the other can only receive at that point of time. E.g. wireless handsets 3. Full Duplex (Duplex): This mode allows both communicating devices to transmit and receive data simultaneously. E.g. Telephone network. Data Communication Measurement. The quantity of data that is communicated is measured in terms of bandwidth. Bandwidth refers to the maximum volume of info that can be

transferred. It is measured in bits per second (BPS) or KBPS. The level of bandwidth falls into 3 categories : 1. Narrow band: Single transmission channel of 64 KBPS or less. 2. Wide Band: 1.544 MBPS to 45 MBPS 3. Broadband: 45 MBPS or more Transmission Media Transmission is the physical media thru which data and info are transmitted. It is divided into 2 categories: 1) Guided media 2) Unguided media. 1. Guided Media: This uses a cabling system that guides the data signal along a specific path. There are 4 basic types of guided media. • Open wire cable, • Twisted pair cable, • Coaxial cable, • Optical Fiber 2. Unguided Media: Data signals flow thru the air. E.g. Radio frequency propagation, Microwave propagation, Satellite. Analog & Digital Data Transmission 1. Analog Signal: It is a continuous wave form that changes smoothly over time. The sine wave is the most fundamental form of an analog signal. Sine waves are characterized by 3 things. a. Amplitude (Magnitude for electrical signals it is measured in volts or amperes) b. Frequency (Measured in Hertz) c. Wavelength refers to the distance between similar points of a given wave measured in Armstrong. 2. Digital Signals: It is the data stored in the form of 0’s and 1’s. Modulation: It refers to the process of impressing information thru a carrier wave by changing some of the wave’s characteristics viz. amplitude, frequency or phase, so that it is more suitable for transmission over the medium between transmitter and receiver. There are 2 forms of modulation 1. Amplitude modulation and 2. Frequency Modulation.

Multiplexing: Multiplexing refers to the process of transmitting more than one signal over a single link, root or channel. There are 2 basic multiplexing techniques 1. FDM (Frequency Division Multiplexing) – Info from multiple channels can be allocated bandwidth on a single wire based on frequency. 2. TDM (Time Division Multiplexing) – Info from multiple channels can be allocated based on time slot. Asynchronous vs. Synchronous Transmission: 1. Asynchronous: It refers to the transmission of one character at a time, with intervals of varying lengths, with start bits at the beginning and stop bits at the end to control the transmission. 2. Synchronous: Here data is sent in blocks without the need for start and stop bits. Switching: Switching refers to routing traffic by setting up of temporary connections between 2 or more network points. A temporary connection is achieved by devices located at different locations on the network called switches. There are 3 methods of switching:1. Circuit Switching: It is a type of communication in which a dedicated channel is established between 2 devices for the duration of the network. E.g. PSTN – Public switch telephone network. 2. Packet Switching: This introduces the idea of breaking data into packets. Each packet contains addresses for the machine sending it and the machine expected to receive it. At The destination the packets are reassembled to form the original message. 3. Message Switching: It uses a message store and forward system where each message contains a destination address and is passed from source to destination thru intermediate nodes. At each transfer point in the connection incoming data is stored in its entirety and then forwarded to the next point. This process continues until the data reaches its destination. Computer Network: A computer network is a collection of 2 or more computers which are connected together to share info and resources. Computers in a network

are interconnected by telephone lines, cables, satellite links, radio or some other communication technique. Networks are primarily categorized into LAN, MAN, WAN according to the size of the network, the distance it covers and the type of link. 1. LAN (local area network) : LAN is a computer network that spans a small geographical area usually within a sq mile or less, viz: a office, home or building. 2. MAN (Metropolitan Area Network): It is a network of computers spread over a metropolitan area viz: a city and its suburbs 3. WAN (Wide area network): it is a system of interconnecting many computers over a large geographic area viz: cities, states, countries or even he whole world. Network Topologies (Network Shapes) The term topology refers to the way a network is laid out either physically or logically. A topology can be considered as the networks shapes. It is geometric representation of the relationship of all the links. There are 5 basic topologies. 1. Bus Topology: This topology network uses a single cable to connect all devices with terminators at both the ends. 2. Ring Topology: In this every node has exactly 2 neighbors connected to form a ring for communication purposes. 3. Star Topology: In this devices are not directly linked to each other but are connected thru a hub forming the shape of a star. 4. Tree topology: Tree topology consists of groups of star configured workstations connected to a bus backbone cable. 5. Mesh Topology: In this every node has dedicated point to point link to every other node. Communication Protocol: A computer protocol is a set of rules that coordinates the exchange of information, both the sending and receiving computers must follow the same protocol, the message gets thru regardless of what types of machines they are and on what operating systems they are running. As long as the machines have software that can manage the protocol, communication is possible. OSI MODEL: The Open system interconnection is a standard reference model between 2 end users in a network. It is used in developing products and understanding networks. In 1983 the International Organization for

Standardization (ISO) published a document called the basic reference model for OSI which visualizes network protocols as a 7 separate but related layered model. These are Physical, data link, network, transport, session, presentation and application. (1 to 4 are included in Lower layer and the rest in the upper layer) Categories OSI layers : The upper layers of the OSI model consists of the application, presentation and session layers and the lower layers consists of the transport, network, data link and physical layers. The physical layer and data link layer are implemented in both s/w and h/w. Physical Layer –It is the lowest of the OSI model and it defines the physical and electrical characteristics of the network. This layer decides about the network interface card, kind of hubs to be used. Data Link Layer (Framing, physical addressing): The function of this layer is to transform the data into a line that is free of transmission errors and is responsible for node to node delivery. It divides the stream of bits coming from the network layer into manageable form known as frames which are transmitted sequentially to the receiver. Network Layer (Logical addressing, routing)- This layer provides the physical routing of the data, determines the path between the sender and the receiver. This layer organizes frames into packets i.e. inbound data is defragmenter in the correct order and then the assembled packet is passed to he transport layer. It manages traffic problems viz. switching, routing, and controlling the congestion of data packets. Transport Layer (Error detection, Recovery) The function of this layer is to handle error recognition and recovery of the data packets. This layer establishes, maintains, and terminates communications between the sender and the receiver. Session Layer (Resynchronization) This layer organizes and synchronizes the exchange of data between the sender and the receiver applications. Presentation Layer (Data encryption, compression) This layer ensures that information sent from the application layer of one system would be readable by the application layer of another system. It also manages security issues by providing data encryption and compression. Application Layer (File transfer, access) This is the entrance point that programs use to access the OSI model and utilize network resources. This

layer represents the services that directly support applications. It includes network software that directly serves the user. Network Devices : There are devices interconnect individual computer and ensure communication process efficiently. These devices are network interface card , HUB, repeater, switch,bridge,and router and get way. NIC : is the first contact between machine and network which connects client’s server and peripheral via photonic is associated with unique address called media access controlled (MAC) helps in sending information to its intended destination. HUB : is a small box that operates by gathering signals from individual network devices optionally amplifying the signal and sending them to other connected devices. Amplification of signals ensure network receive realizable information known as concentrators works on the physical layer of OSI model. REPEATER : It is an electronics device installed on the link receives signals re generates and send the redressed copy back to link. SWITCH : A connector which connects individual devices and communicate with one and other. Network switches are capable of inspecting data packets as they received determining the source destination and forwarding then appropriately which help in reducing overall network traffic. BRIDGE : Filter data traffic at network boundary and inspects incoming traffic to forward or discard it. An Ethernet bridge inspect each incoming frame and makes individual forwarding decision. ROUTER :Router is responsible to trace best route for information to travel. A router creates a table called routing table that store best router to certain network destination. GATEWAY :Is an internet working device known as protocol converter converts the formatted packets in to another protocol.

E-governance: E-governance or electronic governance may be defined as delivery of government services and information to the public using electronic means. Such means of delivering information is often referred to as information technology or 'IT' in short form. Use of IT in government facilitates an efficient, speedy and transparent process for disseminating information to the public and other agencies, and for performing government administration activities. E-governance focus on greater emphasis to improve service mechanism, enhance efficiency of production, Field Services:Digitization,On-site Implementation,System Integration,Project Operationalization,Turnkey Projects Advisory Services Leveraging on our vast experience in E-Governance projects, Comat provides consulting services to various Government organizations. Our Advisory services cover various areas including: • Requirement Assessment and Documentation • Public response assessment and Rural response assessment • Business Process Re-engineering (BPR) • IT Strategy Formulation • IT Architecture and Implementation planning • Hardware and Connectivity requirements analysis • Implementation Strategies • Service delivery models • Facility management • Sustainable revenue models including Private Public Participation (PPP