What is the exact meaning of a header file?

Answer 1

As I understand (I could be wrong though), header file in C++ is used for writing definitions of constants, structures, custom types, function prototypes, etc. It is used so that the implementation source code would be cleaner, not being mixed up with what was placed in the header file, and the separation also helps for later modifications or enhancements.

Hth, cmiiw

Answer 2

A file which should be included in the top of the webpage)

Answer 3

Thanks brother