Graphics in C?

My Data Structures instructor gave me an assignment to animate a stack using graphics in C.

He also told me to use <glut.h>.

What is this header? How to I use it? Do I have to download it separately? Are there any tutorials for this? Are there any other procedures to use graphics in C?

I am using Microsoft Visual Studio 2012 for Windows Desktop on Windows 7, please help.

Let me google that for you

Fordy gave you the answer, but i have to say that just telling you to use glut.h with no background on opengl programming is a pretty rough assignment.