Where is are all the vacuum hoses sourced?

[LtNoogie]

I am wondering if engine vacuum is source at one spot or many places? Does anyone know where all the vacuum hoses lead to?

When I had my car dyno'd the technician t'd off a vacuum hose to see if he could measure boost pressure, which he could not. That makes me think that vacuum is source somewhere after the throttle body but before the S/C blower.

My vacuum/boost gauge is tapped off the intake manifold after the S/C which makes sense.