A laptop computer (also known as notebook computer) is a small mobile personal computer, usually weighing around from 1 to 3 kilograms or 2 to 7 pounds. Laptops are capable of much of what their desktop counterparts can do. They have many of the same components, but they are miniaturized. Laptops usually have LCDs for their screens and smaller SODIMM[?] (Small Outline DIMM) chips for their RAM. They often have a touchpad[?] or a trackpoint[?], but an additional computer mouse or keyboard can be attached.