Networking is a process of connecting two or more devices and allows the sharing of data/information. A computer network is a collection of computers or network devices; connected to one another for the purpose of sharing information among them. If you want to understand network in real life, so Internet is an excellent example of the network.
Figure 3.1- Client Server Architecture
Networking is used to share resources (software and hardware both) such as- file, documents, e-mail, printer, storage, etc. The computer network may be connected using wires/cables (telephone lines, cable TV, fiber optics, etc) or wireless (radio waves, satellite, infrared beams, etc).
Broadly there are two basic forms of computer network design/architecture. As-
• Client server architecture
• Peer-to-peer architecture
In client server network architecture, every computer has a distinct role: that of either a client or a server. A server is featured as a centralized storage, that stores- email, Web pages, files, applications; and designed to share its resources among the client computers on the network. A client computer can communicate only with server computers. A server (or Server Computer) is a single computer or group of servers that are interconnected. A server runs a special network operating system- such as: Windows Server, Linux, UNIX, etc; which is designed to facilitate sharing of its resources among its clients. Figure 3.1 shows client server architecture with single server and ‘N’ clients.
A peer-to-peer (P2P) network is created when two or more computers are connected and share resources without using a separate server computer. Peers are both suppliers and consumers of resources, in contrast to the client-server model in which the consumption and supply of resources is divided in to server and clients respectively.
Figure 3.2- Peer to Peer Architecture
Advantages of Computer Network-
• A network provides the means to exchange data/information among the computers.
• It permits the sharing of the resources of the machine.
• A network provides multiple users to access same data at the same time from same or different locations.
• Video Conferencing is possible through a network
Disadvantages of Computer Network-
• Risk of security issues.
• It encourages people to become dependent on computers.
• A network fault can cause loss of data.
• Complex structure and costlier.
Types of Computer Network
Local Area Network (LAN)
A LAN is a network that is used for communicating among computer devices, usually within an office building or home. It typically consists of several devices (such as-computers and printers) connected to one another in a network. It enables the sharing of resources such as files or hardware devices that may be needed by multiple users. LANs are the most common form of networks found in most small businesses, offices and schools. A LAN can be connected using wired or wireless, when it is connected as wireless then it is named WLAN (Wireless).
Metropolitan Area Network (MAN)
It consists of two or more LANs connected together using high-speed (1.544 Mbps to 155 Mbps) transmission lines. It connects smaller networks (LAN) within a city or town. It is similar to a LAN in a sense that it connects computers but larger in size because it connects two or more LANs in a certain geographic area. A MAN might be owned and operated by a single organization and typically covers an area of 5 to 50 kilometer in diameter. Examples: Telephone company network, Cable TV network, etc.
Wide Area Network (WAN)
It covers a large geographic area such as country, continent or even whole of the world. A WAN is consisting of two or more MANs connected together; as same the MAN is consisting of two or more LANs are connected together. WAN overcome the distance limitations by transmitting data over leased high-speed phone lines or wireless links such as satellites. WANs can use either analog (telephone lines) or digital (such as satellite transmission) signals, or a combination of both.
Applications of Computer Networks-
- It provides a reliable communication medium.
- It provides resource sharing.
- It is used for serving information in remote locations.
- It is used for social media and communication such as e-mail, chatting, video conferencing, messaging, etc.
- It is used for electronic banking.