The Canon S100 is a digital camera, and the Windows driver for it allows your computer to communicate with the camera, enabling you to transfer photos and videos from the camera to your PC, manage files, and sometimes perform other functions like remote shooting or camera settings adjustments. However, the term "driver" in this context is a bit different from the drivers typically used for hardware like printers or graphics cards. In this case, it may refer to the software that enables your camera to interface with your computer.