IBM X31 with 12" screen on an IBM T43 Thin & Light laptop with a 14" screen]] VAIO laptop]]A laptop computer, or simply laptop (also notebook computer, notebook, notepad, and incorrectly labtop;), is a small mobile computer, which usually weighs 2-18 pounds (around 1 to 8 kilograms), depending on size, materials, and other factors. Laptops usually run on a single main battery or from an external AC/DC adapter which can charge the battery while also supplying power to the computer itself. Many computers also have a 3 volt cell to run the clock and other processes in the event of a power failure. As Personal computers, laptops are capable of the same tasks as a desktop computer, although they are typically less powerful for the same price. They contain components that are similar to their desktop counterparts and perform the same functions, but are miniaturized and