A tablet PC is a wireless, portable personal computer with a touch screen interface. The tablet form factor is typically smaller than a notebook computer but larger than a smart phone.
The idea of tablet computing is generally credited to Alan Kay of Xerox, who sketched out the idea in 1971. The first widely-sold tablet computer was Apple Computer's Newton, which was not a commercial success. Technological advances in battery life, display resolution, handwriting recognition software, larger memory, and wireless Internet access have since made tablets a viable computing option.