What does Flip really do?

BlitzMax Forums/BlitzMax Programming/What does Flip really do?

AD: On OpenGL thats right. DX7 one is set to DX texture manager. Don't know if this one keeps all the stuff alive on VRAM if you don't use a texture for a few flips.

But even then, texture rebind isn't a "cheap" thing as well (isn't it the most "expensive" state switch in OpenGL?)