A KVM switch puts one keyboard, monitor, and mouse in control of many computers - at a desk running two machines, at a test bench cycling through builds, or in a server room where one console serves a whole rack. This selection runs from two-port desktop switches to rack-mounted units with console trays and IP access.
Match the video interface and resolution to the monitors first, since video is where KVM compatibility actually breaks, then count ports with growth in mind. For server rooms, decide between local console access and KVM-over-IP early - remote access changes both the hardware and how the room is run, and retrofitting it means rebuying. Cable kits are part of the purchase, not an accessory: most rack KVM units use model-specific cabling, one set per connected machine. COLAMCO quotes KVM switching with cabling and console hardware for business, government, and education server rooms and labs.