What kind of software ?

A device driver, or a software driver is a specific type of computer software, typically developed to allow interaction with hardware devices. This usually constitutes an interface for communicating with the device, through the specific computer bus or communications subsystem that the hardware is connected to, providing commands to and/or receiving data from the device, and on the other end, the requisite interfaces to the operating system and software applications.

Often called simply a driver, it is a specialized hardware-dependent computer program, which is also operating system specific, that enables another program, typically an operating system or applications software package, to interact transparently with the given device. It usually provides the requisite interrupt handling required for any necessary asynchronous time-dependent hardware interfacing needs.