What is a native call?

Gurus,

What is a native function call?
I tried googling but could not get specific information.
Is this the ability to call the subroutine of a language #B from a program written in program #A? (this is my current understanding)
How is this achived?
How does it work?
Are there any standard guiding this?

Thanks in advance,
Satya Prasad

In rough terms, a "native function call" means calling a function that is implemented by, and specific to, the operating system (or family of operating systems).

For example, under most versions of windows (from windows 95 on), applications are able to call functions in the win32 API (with some exceptions, as some functions were introduced into the win32 API with recent versions of windows). The functions in the win32 API could be described by windows programmers as native functions. They are language independent (eg callable by programs written in VB, VC++, .....).