A tablet computer, commonly shortened to tablet or simply tab, is a mobile device, typically with a mobile operating system and touchscreen display processing circuitry, and a rechargeable battery in a single, thin and flat package. Tablets, being computers, have similar capabilities, but lack some input/output (I/O) abilities that others have. Many modern tablets are based on smartphones, the only differences being that tablets are relatively larger than smartphones, with screens from 7 inches (18 cm) to 13 inches (33 cm), measured diagonally, and may not support access to a cellular network. Unlike laptops, tablets usually run mobile operating systems, alongside smartphones.