a) A TV set, or a TV set specifically designed for closed circuit viewing (i.e., from a VTR) without the electronic capability to receive broadcast signals. b) A hardware device that displays the images, windows, and text with which you interact to use the system. It is also called a video display terminal (VDT). c) Program that controls the operation of a microcomputer system and allows user to run programs, examine and modify memory, etc.