hardware programming

when I was taking my graphics introduction class. we were required to implement some of the basic OpenGL functions.
however, since we are using software programming, the rendering was kind of slow.
some advanced students told us that they can use hardware programming, like what OpenGL exactly does. I have no idea what is that.
can somebody explain me a little bit? and how can I starting using this techniqes to further research how opengl works in programming?
P.S. is there a way to take a look at the opengl source code?
From Alan.

I guess you can make your calls directly to the video card (a bit like the playstation 2). But the problem is that the calls are different on each video card… That’s why opengl is here: to make you code compatible with every video cards.