Mainframe Computer

In a traditional mainframe computer environment, each user accesses the mainframe's resources through a device called a terminal (see Fig. 1). There are two kinds of terminals in mainframe computers.
A dumb terminal does not process or store data; it is simply an input/output (I/O ) device that functions as a window into a computer located somewhere else.
An intelligent terminal can perform some processing operations, but it usually does not have any storage. In some mainframe computer environments, however, workers can use a standard personal computer to access the mainframe. Mainframe computers are large, powerful systems (sec Fig. 2). The largest mainframe computer can handle the processing needs of thousands of users at any given moment. But what these systems offer in power, they lack in flexibility. Most mainframe computer systems are designed to handle only a specific set of tasks. In your state's Department of Motor Vehicles, for example, a mainframe computer system is probably devoted to storing information about drivers, vehicles, and driver's licenses, but little or nothing else. By limiting the number of tasks the system must perform, administrators preserve as much power as possible for required operations. You may have interacted with a mainframe computer system without even knowing it. For example, if you have ever visited an airline's Web site to reserve a seat on a flight, you probably have conducted a transaction with a mainframe computer.