A laptop, often called a notebook, is a portable personal computer with a clamshell form factor, suitable for mobile use. Although originally there was a distinction between laptops and notebooks, the former being bigger and heavier than the latter, in modern usage there is often no longer any difference. Laptops are commonly used in a variety of settings, such as at work, in education, and for personal multimedia.
A laptop combines the components and inputs of a desktop computer, including the display, speakers, a keyboard, and pointing devices (such as a touchpad or trackpad) into a single unit. Most modern-day laptops also have integrated webcams and built-in microphones. The device can be powered either from a rechargeable battery or by mains electricity from an AC adapter. Laptops are diverse devices and specialised kinds, such as rugged notebook or convertible computers, have been optimized for specific uses. The hardware specifications significantly vary between different types, makes, and models.
Portable computers, which later developed into modern laptops, were originally considered to be a small niche market, mostly for specialized field applications, such as in the military, for accountancy, or for sales representatives. As portable computers became closer to the modern laptop, they became widely used for a variety of purposes.