(CVA,VAR,glGenFencesNV) == ?

what CVA is?
what VAR is?
what glGenFenceNV is?
I’ve printed OpenGL specs, but I don’t seem they can help me with these things.

These are all OpenGL extensions. CVA’s are Compiled Vertex Arrays, VARs are Vertex Array Ranges. glGenFencesNV is a function in the NV_fence extension. You can find more information about their extensions on NVIDIA’s developer relations website.