I was wondering how I could use the graphics type effectively in C.
I have seen games created in C.
How is that practically possible?

If you looking for the info on game programming more precisely you
can ask this on game programming.

And generally in C , we take generally graphics ( nt game programming) ,
are you done a computer graphics subject or learned elsewhere ?
If not first go and download some MIT free leactures on "Computer Graphics" , it will cover the basics. Then as a starter you can deal with
OpenGL or PHIGS. Study about 3D rendering pipeline, and then so and so you can start other industry demanded technologies , like XNA , DirectX ... and bla bla bla.

FIY I just studying "computer graphics" in this semester and have no
industry level experience. I suggest you to put this post on Game Development section in our Dani Forum.


http://nptel.iitm.ac.in/video.php?courseId=1002
http://nptel.iitm.ac.in/courses/Webcourse-contents/IIT-Delhi/Computer%20Graphics/csmain.htm

may be these leactures and slides will be helpful for you if you nt done a general computer
graphics course. Before starting programming a complex game you should cover the basics.
This is the basics. The basic things include how the graphic pipeline is working , how the line
drawing algorithms are working and bla bla things.... and MIT also contains some free
course ware , just search on gogle.