Driver
Driver is a system program which controls the operation and hence proper functioning of the device .
Common levels of abstraction for device drivers include:
For hardware:
1. Interfacing directly
2. Writing to or reading from a device control register
3. Using some higher-level interface (e.g. Video BIOS)
4. Using another lower-level device driver (e.g. file system drivers using disk drivers)
5. Simulating work with hardware, while doing something entirely different
For software:
1. Allowing the operating system direct access to hardware resources
2. Implementing only primitives
3. Implementing an interface for non-driver software (e.g. TWAIN)
4. Implementing a language, sometimes quite high-level (e.g. PostScript)
D.A.Godse A.P.Godse Fundmentals Of Programming. Technical Publications Pune. 2007, p. 29
Amit Kamra, Pankaj Bhambri Computer Peripherals and Interfaces. Technical Publications Pune. January 2008. pp. 5– 8