Device driver

Device driver is a program or routine developed for an I/O device. A device driver implements I/O operations or behaviours on a specific class of devices. For example a system supports one or a number of multiple brands of terminals, all slightly different terminals may have a single terminal driver. In the layered structure of I/O system, device driver lies between interrupt handler and device independent I/O software. The job of a device driver are following.

• To accept request from the device independent software above it.
• To see to it that the request is executed.