A monitor is a visual output device consisting of a screen with the corresponding electronic circuits, a power supply and the housing. There are a few adjustment controls for operating the monitor functions.
The size of the monitors is mainly determined by the screen size. The specifications refer to the screen diagonal and are in inches, so there are 14", 15", 17", 19", 20", 21" and 23" monitors for office and graphics applications.
In addition, there are application-specific large and special formats. The screen diagonal should always be in reasonable relation to the resolution of the graphic file format. Regardless of the screen diagonal, monitors can be set to different resolutions.