OK. So for example when I use std::cin.get() in my code, the real code that will be replaced by a linker or (if its body is in a DLL and will be executed in RunTime) can be different in each platform. The standard is only for the arguments, return value and the duty of the function, the body can be different.
Am I correct?

How Partition Magic formats a drive for example? How OS let him do its job?