Unattended licensing on Virtual Desktop

What’s the best solution for setting up unattended robots via VD?

License:

Unattended - If High-Density is not enabled on your Robot machines, this license is only dependant on the number of machines you connect to Orchestrator, regardless of the number of users it has.

Does this mean I can set up 10 VD’s on a Windows Server, and have them run at the same time?
If yes, why would you use High-Density robots?

Ref.: about-licensing