Step of writing programme in c language

1 things which comes in c is writing of header file.
header file always ends with (.h).
it is written as
#include<stdio.h>
#include<conio.h>
{this header file is used so that when data is inputed form keyboard the compiler accpeted it and displayes it on rhe screen }
#include<process.h>
{this header file is used to end process.it not nessesary use process.h  }
#include<dos.h>
{this header file is used so that when v can use delay(timer) is program.if dos.h is not use timer cannot be used}
#include<graphics.h>
{this header file is used to use graphics in the program .if not use it will show an error.}