A KVM is a computer input/output device offering the combination of a keyboard, video monitor and mouse. They are typically constructed to fit into a 19-inch rack although there are manufacturers who offer a KVM that can be mounted to a flat surface such as a control console.
Rackmount lay-flat KVM
Triple-screen rackmount LCD display
A computer monitor is an output device that displays information in pictorial or textual form. A discrete monitor comprises a visual display, support electronics, power supply, housing, electrical connectors, and external user controls.
Eizo ColorEdge monitor with screen hood
Hydraulic arm monitor stand, connected via VESA mount holes
A fixed 19-inch (48 cm), 4:3 rack mount LCD monitor
A 1U stowable clamshell 19-inch (48 cm), 4:3 rack mount LCD monitor with keyboard