Chapter – 2 [Information Networks]- Notes

LAN. WAN, MAN, Computer Networks, Information Networks, Internet.

Q. What are information networks?

Information Networks:

• Information networks, or computer networks, are the convergence of two technologies: computing and telecommunication.
• This convergence resulted in LAN (local area network), MAN (metropolitan area network), WAN (wide area network), and the Internet.
• The networks were used for research among computer scientists and telecommunication engineers.
• Information networks have many useful benefits.
• It has also created some problems.
• The most popular information network is the internet, or World Wide Web.
• The users exchange information through the internet.
• The Internet is a large network through which information continuously flows.
• This circulation of information may flow rapidly or slowly.

The main advantages and disadvantages of a computer network are

Q. What is a network? Discuss different types of networks.

Network:

• When two or more two computers are connected through some communication medium, it is called a network.  

OR

• A distributed data processing system is one in which multiple computers are linked together for the purpose of data communication and resource sharing.

Uses of networks:

• Networks allow users to share programs and data at the same time.
• Networks allow users to share peripheral devices.
• Networks allow users to send email messages along with attachments (files).
• Some networks also provide tools for teleconferencing and videoconferencing.

Types of Networks:

There are three types of networks.

1. LAN (Local Area Network)
2. MAN (Metropolitan Area Network)
3. WAN (Wide Area Network)

LAN (Local Area Network):

• It is a digital communication system capable of interconnecting a large number of computers, terminals, and peripheral devices within a limited geographical area.
• It covers a small geographical area, such as an office or a group of buildings, e.g. College Lab, etc.
• Its speed is faster than WAN.

MAN (Metropolitan Area Network):

• A MAN connects an area larger than LAN but less than WAN.
• A MAN covers the geographical boundaries of a city.
• The purpose of MAN is to bypass local telephone companies when accessing long-distance services.

WAN (Wide Area Network):

• It is a digital communication system that interconnects different sites and terminals and also enables different LANs to communicate with each other.
• It covers a large geographical area, such as among cities, countries, or continents, e.g. the Internet. It is also known as a long-haul network.
• The larger computers in a WAN are hosts, and hosts are the computers on the network that provide services to other computers on the network.
• Terminal Emulation Software is used to allow the computer to appear as a terminal.