Structure of C programming language 

1. Header file inclusion

The first and important thing is to include header file in C program. Header file is a file 

with extension .h which contain function declaration and definition of predefine function.

Some of the header files are as follows

<stdio.h> Defile core input and output

<math.h> Define common mathematical operation

<string.h> Define string handling function.

2. Main method

It is entry point of C program. Execution typically begins with first line of main method. 

The int written before main indicate return type of main.

3. Body of main method

It contains statement that are part of function. All function must start and end with curly 

brackets.

4. Statement

Statements are the instruction given to compiler. Statement is always terminated by 

semicolon (;).

5. Return statement

The last part of c program is return statement. It refers to written values from a function. 

This may be used by an operating system to know termination status of your program. 

The value 0 typically means successful termination.