By Dinesh Thakur

A computer network consists of two or more computers that are linked in order to share resources such as printers and CD-ROMs, exchange files, or allow electronic communications. The computers on a computer network may be linked through cables, telephone lines, radio waves, satellites, or infrared light beams.

We’ll be covering the following topics in this tutorial:

Networks constitute systems formed by links. Websites that allow people to create links to each other with their pages are called social networking sites. A set of related ideas can be called a conceptual network. The connections you have with all your friendscan be called your personal network.

The following networks used every day:

• Mail delivery system. • Telephone system • Internet. • Public Transportation System. • Corporate computer network.

Computers can be connected by networks to share data and resources. A network can be as simple as two computers connected by a single cable or as complex as hundreds of computers connected to devices that control the flow of information.

Converged data networks can include general-purpose computers, such as personal computers and servers, as well as devices with more specific functions, such as printers, phones, televisions, and game consoles.

All converged networks of data, voice, and video share information and use various methods to direct the flow of information. The information on the network moves from one place to another, sometimes by different routes, to reach the correct destination.

The public transport system is similar to a data network. Cars, trucks, and other vehicles are like the messages that travel on the net. Each driver defines the starting point (origin) and the endpoint (destination). In this system, there are rules, such as stop signs and traffic lights, that control the movement from origin to destination.

By completing this section, you achieve the following objectives:

• Define its computer networks. • Explain the benefits of networking.

A data network consists of a set of hosts connected by network devices. A host is any device that sends and receives information on the network. Peripherals are devices that are connected to hosts. Some devices can act as hosts and peripherals. For example, a printer connected to a laptop that is on a network acts as a peripheral. If the printer is connected directly to a network device,such as a hub, a switch or a router, it acts as a host.

Computer networks are used globally in companies, homes, schools, and government agencies. Many of the networks connect through the Internet.

It is possible to connect various types of devices to a network:

• Desktop computers. • Laptops. • Printers • Scanners • Personal digital assistants (PDA). • Smartphones. • Print and file servers.

A network can share many types of resources:

• Services, such as printing or scanning. • Applications, such as databases. • Storage space on removable devices, such as hard drives or optical drives.

Networks can be used to access information stored on other computers, print documents using shared printers, and synchronize the calendar between your computer and your smartphone.

Network devices connect through various connections:

• Copper wiring: uses electrical signals to transmit data between devices. • Fiber optic cabling: uses plastic or glass cable, also called fiber, to transport information as the light emitted. • Wireless connection: uses radio signals, infrared (laser) technology, or satellite transmissions.

The benefits of networking on computers and other devices include low costs and higher productivity. Thanks to networks, resource scan be shared, which reduces data duplication and corruption.

Every computer on the network does not need its printer, scanner, or backup device. It is possible to configure several printers in a central location and share them among network users. All network users send print jobs to a central print server that manages printr equests. The print server can distribute print jobs among the various printers, or it can queue jobs that require a particular printer.

Networks offer various collaboration tools that can be used to establish communications between network users. Online collaboration tools include email, forums and chat, voice and video, and instant messaging. With these tools, users can communicate with friends,family, and colleagues.

A server manages network resources. The servers store the data and share it with the users of a network. Confidential or essential data can be protected and shared with users who have permission to access such data. Document tracking software can be used toprevent users from overwriting or modifying files that other users are accessing at the same time.

Acquiring application licenses can be expensive for individual computers. Many software providers offer site licenses for networks,which can significantly reduce the cost of the software. The site license allows a group of people or an entire organization to usethe application for a single fee.

Centralized administration reduces the number of people needed to manage devices and data on the network, allowing the company to save time and money.

Individual users of the network do not need to manage their data and devices. An administrator can control the data, devices, and permissions of network users. Creating backup copies of the data is more comfortable because of the data stored in a central location.

It is possible to distribute data processing among many computers to prevent a computer from being overloaded with processing tasks.

Computer network can be classified on the basis of following features : By Scale: Computer networks may be classified according to the scale : • Local Area Network (LAN) • Metropolitan Area Network (MAN) • Wide Area Network (WAN)

By Connection Method: Computer networks can also be classified according to the hardware technology that is used to connect the individual devices in the network such as Optical fibre, Ethernet, Wireless LAN. • Client-Server • Peer-to-Peer Architecture

By Functional Relationship (Network Architectures) : Computer networks may be classified according to the functional relationships which exist between the elements of the network. This classification also called computer architecture. There are two type of network architecture

By Network Topology: Network Topology signifies the way in which intelligent devices in the network see their logical or physical relations to one another. Computer networks may be classified according to the network topology upon which the network is based, such as : • Bus Network • Star Network • Ring Network • Mesh Network • Star-Bus Network • Tree or Hierarchical Topology Network

The following are the distinct notes in favor of computer network.

a. The computers, staff and information can be well managed

b. A network provides the means to exchange data among the computers and to make programs and data available to people

c. It permits the sharing of the resources of the machine

d. Networking also provides the function of back-up.

e. Networking provides a flexible networking environment. Employees can work at home by using through networks ties through networks into the computer at office.

1. Network services are the thing that a network can do. The major networking services are

2. File Services: This includes file transfer, storage, data migration, file update, synchronization and achieving.

3. Printing Services: This service produces shared access to valuable printing devices.

4. Message Services: This service facilitates email, voice mails and coordinate object oriented applications.

5. Application Services: This services allows to centralize high profile applications to increase performance and scalability

6. Database Services: This involves coordination of distributed data and replication.