A tablet computer , commonly shortened to tablet, is a mobile computer with a touchscreen display, circuitry, and battery in a single device. Tablets come equipped with sensors, including cameras, a microphone, and an accelerometer, and the touchscreen display uses the recognition of finger or stylus gestures replacing the usage of the mouse and keyboard. They usually feature on-screen, pop-up virtual keyboards for typing. Tablets may have physical buttons for basic features such as speaker volume and power, and ports for network communications and battery charging. Tablets are typically larger than smartphones or personal digital assistants with screens 7 inches (18 cm) or larger, measured diagonally.