A computer monitor is a hardware component of a computer that displays information through a visual interface. The monitor is composed of a case and a screen that displays the information.
Computers have been built in many different forms since their invention. Early computers did not have the clear and practical monitors of modern day. Monitors make it much simpler to see what information has been inputted through a keyboard, mouse or other input device, and also to see what information the computer has output. While the monitor is typically considered part of a personal computer, no computing actually takes place in the monitor hardware.