KVM stands for Keyboard, Video, Mouse.
A KVM allows you to use and control many computers with a single keyboard, video display, and mouse.
You plug in a single keyboard, video display, and mouse into a KVM. Then plug in all the other computers you want to control. You can being controlling one computer with your keyboard, viddo display, and mouse then push a button or use a keystroke to switch to a different computer. This second system will then send it’s keyboard, video display, and mouse signals to the same keyboard, video display, and mouse you were initially using.