How to utilize 2d/3d Graphics Acceleration on a Single Board Computer

Question

This may be a somewhat silly question, but if you are working with a single board computer that boasts that it has 2d/3d graphics acceleration, what does this actually mean?

If it supports DirectX or OpenGL obviously I could just use that framework, but I am not familiar with working from this end of things. I do not know if that means that it is capable of having those libraries included into the OS or if it just means that it does certain kinds of math more quickly (either by default or through some other process)

Any clarification on what this means or locations of resources I could use on such would be greatly appreciated.