What is the Difference Between Header File and Library File?

The main difference between a header file and a library file lies in their content and purpose in the software development process. Here are the key differences:

• Header File:
• Contains function declarations, data types, and constants used with the libraries.
• Has a text format, making it human-readable.
• Instructs the compiler how to call the functionalities.
• Includes the function prototypes, which describe the function's return type, parameters, and calling convention.
• Used with the #include directive in the source code.
• Library File:
• Contains the actual function definitions and implementations.
• Has a binary format, making it non-human-readable.
• Implements the functionality that the header file describes.
• Linked to the compiled source code at the last stage of the compilation process, usually by a special software called a linker.

In summary, a header file provides the necessary information for the compiler to call functions and use libraries, while a library file contains the actual implementation of those functions and libraries. The header file is used with the #include directive, while the library file is linked during the compilation process.

Comparative Table: Header File vs Library File

Here is a table comparing the differences between header files and library files:

Header files contain the function prototypes and declarations of data types and constants used with the libraries, while library files contain the actual function definitions and implementations. Header files are human-readable and are included in programs using the #include directive, while library files are in the form of machine code and are included in the last stage of the compilation process by a special software called the linker.