What Is A Header File In C? A header file in C language is a text file containing definitions of functions, variables, and macros that are shared among multiple source files. It provides an interface to the variety of functions and data structures that can be used by other parts of the program. Essentially, a header file serves as a contract that specifies what features/ operations are available to the rest of the program without exposing the implementation details. Standard Header File In C & Their Uses In C, there are many standard header files, each of which has a unique collection of utilities and methods. Naturally, there are a few standard C header files that are most typically used in applications/ C code. We have compiled a detailed explanation of all 25 standard header files in C. The <stdio.h> Header File In C The name stands for standard input/output header , and it contains functions for standard input and output operations such as...