A laptop or a notebook is a portable personal computer with a clamshell form factor, suitable for mobile use. Although there used to be a distinction between laptops and notebooks (the former were bigger and heavier than the latter), there is often no longer any difference in practice. Laptops are commonly used in a variety of settings, including at work, in education, and for personal multimedia.
A laptop combines the components and inputs of a desktop computer, including display, speakers, keyboard and pointing device (such as a touchpad or a trackpad) into a single device. Most modern-day laptops also have an integrated webcam and a microphone. A laptop can be powered either from a rechargeable battery, or by mains electricity via an AC adapter. Laptop is a diverse category of devices and other more specific terms, such as rugged notebook or convertible, refer to specialist types of laptops, which have been optimized for specific uses. Hardware specifications change significantly between different types, makes and models of laptops.
Portable computers, which later developed into modern laptops, were originally considered to be a small niche market, mostly for specialized field applications, such as the military, accountancy, for sales representatives etc. As portable computers developed and became more like modern laptops, becoming smaller, lighter, cheaper, and more powerful, they became very widely used for a variety of purposes.