Many touch enabled devices include only a limited set of physical keys.
For backwards compatibility with Canvas applications,
Touch UI utilizes an on-screen keypad (OSK).
Touch enabled devices with limited or no physical keys offer different
kinds on-screen keypads for Canvas applications. Events
from available keys in on-screen keypad map the same way as events from physical
keys.
For more detailed descriptions of using on-screen keypads in different devices, see the following sections: