A tablet computer, or simply tablet, is a complete mobile computer, larger than a mobile phone or personal digital assistant, integrated into a flat touch screen and primarily operated by touching the screen. It often uses an onscreen virtual keyboard or a digital pen rather than a physical keyboard.

The term may also apply to a "convertible" notebook computer whose keyboard is attached to the touchscreen by a swivel joint or slide joint so that the screen may lie with its back upon the keyboard, covering it and exposing only the screen for touch operation.

As of 2010, two distinctly different types of tablet computing devices exist, whose operating systems are of different origin.

Older tablet personal computers are mainly x86 based and are fully functional personal computers employing a slightly modified personal computer OS (such as Windows or Ubuntu Linux) supporting their touch-screen, instead of a traditional display, mouse and keyboard. A typical tablet personal computer needs...