What is the meaning of stdio.h and it's use for what?

Are we talking about computer programming? cstdio (stdio.h) - C++ Reference (http://www.cplusplus.com/reference/clibrary/cstdio/)

Stdio.h is a librairy of c++ standard IO function by adding #include <stdio.h> at the beginning of your code give you access to all those function in your code.

For example printf, scanf etc are all include in that librairy

Hope that was useful