GL/glut.h header

There are some sample progammes available at
which i can make use of, but i’m not sure what is inside this #include <GL/glut.h> header file…
As such, i’m not able to compile the code to use it in my programme…
Does anyone out there happen to know what is inside this #include <GL/glut.h> header file??
Do i have to create it myself or is it available in the library??

This page should give you a good explanation what GLUT is and where to get it.