Computer terminals have the seemingly simple function of allowing input into a larger computer system and, potentially, receiving information back from it. One of the most common types of computer terminal is a monitor and keyboard setup that is connected to a larger computer through a network interface. Other types of computer terminals include handheld terminals and dedicated devices such as credit card reading terminals and point of sale terminals. With the proliferation of inexpensive computer hardware, fully functional computer systems can be employed as terminals by using terminal emulation software to access the larger mainframe computer.
The simplest of the computer terminals is called a dumb terminal. This can be something as basic as a monitor and keyboard plugged directly into a network router, or it can be a computer with an actual tower unit that is networked in an office. The reason the terminal is considered dumb is because it has close to no processing power of its own and instead just sends and receives signals from a larger central computer that performs all the processing. Dumb terminals are both inexpensive and secure because they are unable to save information to a local hard drive and must route all information and requests through the main computer system.
Above dumb terminals are intelligent computer terminals. These are actual functioning computers or laptop systems that do have the basic components of a standard personal computer, including a hard drive, memory and peripheral ports. These terminals are networked to a central computer system and can work in one of two ways. They can run custom client software to interface with the mainframe, or they can use terminal emulation software to mimic a dumb terminal in a dedicated window. An intelligent computer terminal has the advantage of allowing some processing tasks to be performed by the local processor instead of relying solely on the mainframe for all actions.
Handheld computer terminals are often employed in industries that require employees to move around a lot or to be in different locations over the course of a day. These terminals can either resemble small computers with miniature keyboards and monochrome displays, or can be customized to input specific types of data more efficiently. Different types of handheld computer terminals are widely used in surveying, manufacturing, financial trading and inventory control companies.
Other types of computer terminals can include computerized cash registers that are really just dumb terminals that have been customized to allow for faster input of specific information. Networked terminals are similar to intelligent computer terminals except all the software run on them is drawn from the mainframe, though the local computer actually runs the programs once retrieved. Finally, there are transaction terminals that perform functions such as reading credit cards or allowing access to a bank account; an automated teller machine (ATM) is one such example.