The vacuum in your workshop has a lot in common with your compressor.
The vacuum removes air from somewhere, and the compressor pumps air into an air tank or air system.
The end result of both is stored energy. If your vacuum, was used to pull air from a tank, and that tank was then sealed, you would have stored energy in the form of absence of air. In your compressor tank, the charge of air at 120 or 150 PSI (or whatever your compressor is rated for) is stored energy.
Both the vacuum tank and the compressed air tank use the phenomenon that nature wants things to be in balance to do work.
In the case of the compressed air tank, when the air tool is turned on or the downstream valve is activated, it’s that air rushing from a high pressure area back to atmoshpere that we use to do work.
In the case of the vacuum tank, it’s the air rushing from a higher pressure area into a very low pressure area that we use to do work.
What prompted this post is this article I read about a central vacuum system in the UK that’s a cut above your typical vacuum system. This is very interesting reading.