Boards like TinkerBoard (RK3288) have a Video Processing Unit. Is that a physical chip? It's inside the Mali GPU? Or it's a virtual thing?
The Mali GPU is not a physical chip in its own right, it's one logical component inside the full system-on-a-chip silicon die.
For example, see this teardown of a Samsung chip containing a Mali GPU: https://www.techinsights.com/about-techinsights/overview/blog/samsung-galaxy-s9-teardown/
The VPU is an independent component to the GPU, yes.
HTH, Pete