• A user who has a computer at home would use it for most of his work and connect the video terminal of the personal computer to a big computer for solving larger programs and to access special library programs and data resident in the big computer.
• A smaller organisation may not have work load to justify an in house computer. In such a case they buy a workstation or aPC, place it in their premises and connect it as a time sharing terminal to a large computer via a telephone lines. This allows them to conveniently access a larger machine without having to make frequent trips to the computer centre.
• Some information centres store amounts of data on patents, technical reports, journal articles,etc in an organised fashion. A user requiring specific information, can connect his terminal through a telephone lines to a large computer and retrieve the information using appropriate descriptors.
• Some information centres are connected to the international fax networks and it would be possible to send enquiries via fax to such centres.
• Local area networks are used to inter connect many computers with in an organisation. This helps in sharing files, sharing programs and decentralise specialised functions.
• Certain local area networks are created to a share the use of expensive peripherals such as fast privaters, large disks, graphics, workstations etc. Some of them are used for laboratory enviroment.
• Local area networks are used in factories for controlling plant and processes. Individual computers are installed to monitor and control critical processes in the plant.
• Computer network are mainly used to connect a number of widely dispersed computers. The main objective is to create access to library programs, databases, languages and special facilities available in any of the computers in the network.
• One of the computer in the computer network provides specialised services such as patent information database or bibliographic database

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