A laptop and desktop computer differ in both size and functionality. A laptop is much smaller and therefore often more convenient to use.A desktop computer is much larger, and tends to last much longer than a laptop before it needs to be repaired or replaced. A laptop is often a self-contained unit, and no additional parts are needed to run it. Users often have to purchase monitors and other accessories to operate a desktop computer.

There is little to no difference in the types of software that can be run on each type of computer.
The size is the most noticeable difference between a laptop and desktop computer. A laptop is a single machine with the hard drive, disk drive, monitor, wireless modem, keyboard and mouse contained within it, and it easily folds to be stored in a carrying case. The only additional accessory that is often needed is a power cable with an adapter attached to it. A desktop computer consists of a tower, which is a large rectangular box. The hardware for the computer system is contained in the box. An external monitor, keyboard, mouse and wireless router often need to be attached to a PC in order to fully operate it.