Desktop PCs are computers that sit on or under a desk. In contrast to a laptop or tablet, a desktop computer is designed to be used in a single location. Desktops come in various shapes and sizes (or form factors) running from a full sized tower PC down to an ultra small form factor PC and even a stick PC that resembles a flash/pen drive that can plug into a monitor for basic tasks. Typically, a desktop PC is supplied with a power cable, keyboard and mouse but you would need to connect it up to one or more monitors to be able to use it.