What are all the sections that a C program may have and must have?

Question

Accepted Answer

There are many sections in a C program structure. They are,
 

Documentation section
Link Section
Definition Section
Global declaration section
Function prototype declaration section
Main function
User defined function section

main() function section is the important section in a C program as program execution starts from main() function only in C language. A C program may not have all other sections except main() function.

What are all the sections that a C program may have and must have?

Answer with Explanation