• When several computers are conncected to each other with a common purpose that
  computer system is known as a computer network.
• Several computer networks can be identified based on the way the computers
  are connected in a particular network, They are:
  • Bus network
  • Ring network
  • Star network
  • Tree network

Categories of computer networks according to the Geographical dispersion

• Local Area Network (LAN)
• Wide Area Network (WAN)

There are several computer networks based on the party used or objectives of using:

• Intranet
• Extranet
• Internet

• Internet can be stated as the network of networks.
• An individual or an institute can obtain internet facilities through an internet service provider (ISP).

Services provided by Internet 

• World Wide Web (WWW)
• E-mail
• File Transfer Protocol
• Chatting facilities
• News group
• Tele Computing