What is OpenGL?
OpenGL is a 3D graphics API used for high-end graphics and animation. OpenGL was originally created by Silicon Graphics Inc (SGI) in effort to simplify the code required to write 3D applications by bridging the gap between software and hardware. It can be used for games, screensavers, web graphics, etc. It uses the new 3D video cards' specialized ability to render 3D graphics very quickly. This is often called "3D hardware acceleration." And in case you were wondering, GL stands for Graphics Library.
Why do I need OpenGL?
Without hardware-accelerated OpenGL many of the latest video games would not run, or would run very slowly. OpenGL combined with your video card will accelerate graphics a considerable amount, and allows a higher level of visual quality.
Where do I get OpenGL?
Most computers will already include OpenGL runtime drivers which will allow you to run programs that require it. But if you think that you might need new drivers because you can't run certain programs or games, then you should go to your video card manufacturer's website to obtain the latest video card drivers. If you still have issues with the latest drivers then there's a good chance you're in need of a new video card.