How do vacuum systems and air systems in chemistry labs work?

In student labs and research labs for chemistry and some other fields there are usually cylindrical things (I’m not really sure what they’re called) that supply air, gas and vacuum suction. How do these work? Is there a central repository of high pressure air in tanks somewhere in the building, and a large vacuum pump?

I know that in the first building the biotech company I used to work for was housed in the vacuum system was in fact just connected to a large pump.

I believe the compressed air systems are separate but I am not sure if they are usually done by compressors or by tanks. You can certainly buy tanks of what is called medical grade compressed air, we used them to feed oxygen into bioreactors. This probably wouldn’t be efficient for a whole building though.