Once upon a time ... Nintendo, a game maker, innovates the world game experiences with a totally new concept: get physical (as to prevent you from getting ‘finger/thumb-RSI’). This striking new phenomenon is the nowadays well known Wii game, played with its remote objects, the Wii Remote (a.k.a Wiimote) and its companion, the Nunchuk.
As time goes by, clever people discover other possibilities for, in this case, the Wiimote. With some dedicated software you can turn it into a PC device, impersonating the standard mouse.