How it works
A KVM switch shares keyboard, video and mouse connections between multiple computers. It usually selects which computer receives the controls and screen connection; it does not merge the computers' files or accounts. A keyboard-and-mouse-only switch is different because each computer may retain its own display. Multi-monitor KVM models also require the appropriate number of display paths from each computer.
Compatibility includes video bandwidth, resolution, refresh rate, USB features and the cables on every branch. A basic keyboard may work through an emulated keyboard port while a device with extra functions needs a supported USB hub connection. Docked laptops introduce another layer of display capability and power requirements. Screen detection during switching can also affect window placement, depending on the switch's supported display emulation and the operating system.
Practical checks
Inventory computers, screens and peripherals before choosing a switch. Check their interfaces and the exact picture mode you intend to use rather than only counting sockets. Test each computer directly first, then add the switch and confirm video, keyboard, mouse and any shared accessories separately. Keep transfers complete before switching storage peripherals. If a feature fails, compare the documented port type and supported functions instead of assuming every USB-shaped connection behaves identically.