A laptop (or notebook)is a personal computer for mobile use. It integrates most of components of a PC, including a display, a keyboard, a pointing device (a touchpad) and speakers into a single unit. They typically measure 12–15 inches wide by 8–11 inches, and 1–2 inches in height and weigh around 3–4 kilograms. It is powered by mains electricity via an AC adapter, and can be used away from an outlet using a rechargeable battery. A laptop battery in new condition typically stores enough energy to run the laptop for three to five hours, depending on the computer usage, configuration and power management settings. When the laptop is plugged into the mains, the battery charges, whether or not the computer is running and with usage battery’s energy storage reduce to a few minutes.
Laptops now are smaller, lighter, and cheaper and as screens became larger and of better quality, laptops became very widely used for all sorts of purposes.