Geographic Information Systems: An Introduction, 3rd Edition

7.2 Networks

Information is one of the most important strategic factors facilitating development in any area. Modern political and economic systems cannot function without a continuous interchange of reliable information. Worldwide, the communication and distribution of data is a large and rapidly growing sector.

The term network is used here to mean data systems linked together by electronic lines of communication and software. There has been a considerable increase in the use of networks in recent years, due to the following factors:

• Exchange of data between systems (users)
• Sharing of expensive resources (equipment)

The basis of network technology is that individual units in the system comprise common resources (server) for the rest of the network (clients). A server normally has a greater data storage capacity than the other computers in the system and is capable of handling complex program systems. Local networks are available that link local data equipment—for example, in the same building, for sharing of data storage capacity and software, as well as printers, plotters, and so on.

HUBs are used as nodes between computers, enabling different machines in the network to communicate with each other. Local networks, often called LANs (local area networks; Figure 7.3), and remote networks, often known as wide area networks (WANs), link computers together over greater distances (Figure 7.4). WANs are based on the services of national/international telecommunications companies. ...