What is lower-level on Windows: the C library or corresponding Win32 API functions?

Question

I've been wondering which is implemented in terms of which. My guess goes to eg fopen being implemented using OpenFile. From what I can tell, the Win32 API is more complete than the MSVC C library implementation, so my guess would make sense.

Is this correct, or is it the other way around?

Answer 1

Yes, Win32 is a "lower-level" API than the standard C-library ... basically the standard C-library on Windows is an abstraction of native Windows syscalls that allows certain standard operations to remain compatible across any series of platforms that support the C-standard library. Each platform will have it's own implementation of the C-library based off internally native system calls.