A relationship between an application programme the operating system and hardware

The relationship between an application programme the operating system and hardware is usually shown in the form of a stack of lawyers as shown below :

1. application

2.application program interface

3. operating system

4. device driver

5.hardware

most application needs to know how to talk to operating system which is why the operating system will provide a set of proggramming libries knows as APIs or SDKs for proggremers use whenwriting application.

the APIs sit between the operating system and the running application . the running application relies on the api to perform essential on the computer by telling the operating system what is wants to do which is why a program thats is written to use Windows Vista APIs will not run on an Apple Mac without some kind of emulation or help.

Because there are so many different pieces of hardware , it would be impossible for an operating system to support them all . thats why hardware manufactures will write device drivers for different operating system , so the operating system knowns how to talk to the hardware .