A virtual keyboard is a software component that allows the input of characters without the need for physical keys. Interaction with a virtual keyboard happens mostly via a touchscreen interface, but can also take place in a different form when in virtual or augmented reality.
Typing on an iPad's virtual keyboard
Virtual keyboard on a Pocket PC PDA
Apple iOS UIInputViewController
In computing, an input device is a piece of equipment used to provide data and control signals to an information processing system, such as a computer or information appliance. Examples of input devices include keyboards, computer mice, scanners, cameras, joysticks, and microphones.
Ergonomic keyboard
Chorded keyboard
Thumb keyboard
Keyer