Nothing to be sorry for - this is a good question.
While the air flow rate and depth of the vacuum certainly differ across vacuum devices, there is a factor that greatly affects the choice of a device. This factor is how long is the motor designed to run.
Home vacuums are just not designed to run for hours - minutes usually. Shop vacs are set up to run longer - a hour or so but not much more. Formal dust collectors are designed to run for many hours per day, day in and day out.
Expect to wear out a home vacuum pretty quickly if you use it as a CNC dust collector. A shop vac is going to last longer - a year or two. A dust collector (e.g. Festool CT 26; Fein xxx) can run for hours every day for years and still be fine.
While it is worth it to go with a formal dust collector - certified air safety - they are pricey and out of range, budget wise, for many.
The vacuum element takes air in - causing a vacuum - and spits air out. We do not want the particles in the air to spit out with the air, hence the filters. With CNC, the particles can be very small - too small for the eye to see - and very dangerous to lung safety. We need a filter that removes the nasty stuff or the filter isn’t really doing much for us.
The HEPA filter - 0.3 micron rating - is a standard to ensures that one has the filtering necessary to protect your lungs. The UL, EPA, and EU recognize and accept this; fire fighters masks use HEPA filters.
So, a home vacuum with a HEPA filter is a fast way to go through vacuums. Probably not what one intends. A shop vac tends to be cheap so one goes through them once in a while - as long as the HEPA filter is real and installed so it doesn’t leak - it’s not to expensive or painful.
HEPA filters are… expensive. $60 or $80 is not uncommon. We use a cyclone in front of the vacuum element to remove up to 99+% of the particles before we hit the filter. The cost tradeoff is often rather fast, especially if one machines a lot of wood or Renshape.
The air flow rate and depth of the vacuum ARE factors that are important for particle “lofting” (ensuring they are picked up by the vacuum). It is very, very hard to get acceptable, honest ratings for those for a (home) vacuum; less difficult for a shop vac and easily known for a dust collector.
Another factor is… noise. Our Nomad is designed to be inside the house, one would not be happy with a very loud vacuum element running for hours.
A great deal of math and physics goes into a good vacuum. With a small format machine like the Nomad, we’re not going to achieve near perfection. The good news is we can do quite a bit to ensure air safety. A Festool is cool but we don’t have to break the bank to achieve very good results.
How to design an acceptable system depend on venting - where does the output air go. If one can always dump it outside (and ensure it doesn’t come back in!) the task is much simpler and cheaper than if the air is dumped inside.
Keep asking those questions,