What does #include actually do?

Question

In C (or a language based on C), one can happily use this statement:

#include \"hello.h\";

And voila, every function and variable in

Answer 1

This is a nice link to answer this question.

http://msdn.microsoft.com/en-us/library/36k2cdd4.aspx

Usually #include and #include "path-name" just differs in the order of the search of the pre processor