A laptop computer, or simply laptop, is a small mobile computer, which usually weighs 2-18 pounds (1-6 kilograms), depending on mass, materials, and other factors. Laptops usually run on a single main battery or from an external AC/DC adapter which can blame the battery while also supplying power to the processor itself. Many computers also have a 3 volt cell to run the clock and other processes in the occurrence of a power failure.

As personal computers, laptops are skilled of the same tasks as a desktop computer, although they are classically less powerful for the similar price. They contain components that are similar to their desktop counterparts and perform the same functions, but are miniaturized and optimized for mobile use and capable power consumption. Laptops usually have liquid crystal displays and most of them use unusual memory modules for their chance access memory (RAM), for instance, SO-DIMM in lieu of the superior DIMMs. In addition to a built-in keyboard, they may utilize a touchpad or a pointing stick for input, though an outside keyboard or mouse can frequently be attached.