A key component among tablet computers is touch input. This allows the user to navigate easily and type with a virtual keyboard on the screen. The first tablet to do this was the GRiDPad by GRiD Systems Corporation; the tablet featured both a stylus, a pen-like tool to aid with precision in a touchscreen device as well as an on-screen keyboard.
The system must respond to touches rather than clicks of a keyboard or mouse, which allows integrated hand-eye operation, a natural use of the somatosensory system. This is even more true of the more recent multi-touch interface, which often emulate the way objects behave.
As with smartphones, most mobile tablet apps are supplied through online distribution, rather than boxed software or direct sales from software vendors. These sources, known as “app stores”, provide centralized catalogues of software and allow “one click” on-device software purchasing, installation and updates. The app store is often shared with smartphones that use the same operating system.