Understand High-Level Drivers with API.

A "Driver" is a piece of software used to access the functions of a semiconductor chip. It is intended as an integration layer to assist development of application software, which require functions provided by the chip.

Drivers can be implemented in many ways. Low-level drivers simply provide a software access to chip "registers" (the chip-memory tables holding information used by the chip). Using low-level drivers requires extensive knowledge of the chip architecture and for complex chip designs, can complicate application software development.

High-level drivers provide an abstraction layer, which hides the complexity of the chip architecture from the application software developer. Extra functions are implemented in the driver to emulate a "work-flow" for typical tasks. This allows a single application software command to result in a series of chip level function calls hiding the complexity and intracacy from the programmer. It also ensures that fewer mistakes are made.

An Application Programming Interface (API) extends this concept to include an easy to use interface for application software programmers. The API "calls" can be implemented as part of the application software code making integration with the driver, and thereby the chip, easier.

The following link describes device drivers for different computing applications: http://en.wikipedia.org/wiki/Device_driver

See more on APIs here: http://en.wikipedia.org/wiki/Application_Programming_Interface