A computer monitor is an electronic output device that displays information in pictorial or textual form generated by a connected computer via a computers video card. It is also known as a video display terminal (VDT) or a video display unit (VDU) . The display in modern monitors is typically an LCD with LED backlight, having by the 2010s replaced CCFL backlit LCDs. Before the mid-2000s, most monitors used a CRT. Monitors are connected to the computer via DisplayPort, HDMI, USB-C, DVI, VGA, or other proprietary connectors and signals.

There are three types of computer displays: CRT, LCD, and LED. CRT monitors are big and heavy and use a lot of desk space and electricity. They are based on the cathode ray tube technology that was developed for television. LCD monitors use much less desk space, are lightweight, and use less electricity than CRT. They have been used for many years in the screens of laptop and notebook computers. They also work as touch screens in tablet computers, mobile phones, and other handheld technologies. LED monitors are LCD monitors that use light-emitting diodes for backlighting.

The primary use of a monitor is to display images, text, video, and graphics information generated by the computer via a computers video card. It is the main visual display of a computer as it displays everything that is being processed inside the CPU. Monitors require one of the following kinds of connectors or components to connect with a computer: VGA (Video Graphics Adapter), DVI (Digital Visual Interface), HDMI (High Definition Multimedia Interface), DisplayPort, Thunderbolt, or USB-C.

In summary, a computer monitor is an electronic output device that displays information generated by a connected computer via a computers video card. It comes in different types, such as CRT, LCD, and LED, and is connected to the computer via various connectors and signals. Its primary use is to display images, text, video, and graphics information being processed inside the CPU.