Module 1, Concepts of Information and Communication Technology (ICT)

• A mainframe is a centralised computer capable of serving large numbers of users at the same time. Mainframes tend to be used less since the speed of desktop PCs has increased and the cost decreased. It is far more cost effective for a company to buy standard PCs that are networked together than a single mainframe nowadays.

• Users do not sit down in front of the mainframe computer itself. They connect to it using another smaller computer or a dumb terminal. (A dumb terminal usually consists of a keyboard and screen, and simply enables a user to connect to and use the mainframe computer. A dumb terminal does not process or store any data itself, ie it is not intelligent.)
  
  
• Because mainframes need to process and store information for many different users at once, they require much more processing power and storage capacity than other computers, i.e. they need to be faster and have more memory. The result is that they tend to be very expensive.
  
  
• Mainframes are often used by large corporate and government data processing departments, where many users need access to large amounts of information. Mainframes allow this information to be centrally stored and controlled. They also offer more power and require less maintenance than clusters of smaller computers.

Every time you use an automatic cash dispenser at a bank, you are using a small computer (the cash dispenser) to access a central mainframe computer that stores information regarding your account.