These are the two system architectures most homeowners actually choose. Portable + interlock: you roll or park the generator, start it, and select loads. It is cheaper, more flexible, and it needs a person and fuel on site. Standby + ATS: the unit sits on a pad, usually on natural gas or propane, starts itself, and transfers the house or a large load center. It costs much more and covers the house when no one is home.
A third option in the same r/Generator ELI5 threads is a portable generator with a manual essential-circuit transfer switch — less flexible than an interlock, more foolproof about which circuits can be on. Fuel logistics matter as much as watts; gasoline during a multi-day outage is a recurring complaint, which is why some owners look at tri-fuel or natural-gas portables, still with manual transfer.
Neither architecture makes a dryer-outlet backfeed acceptable. Size loads with the calculator before you shop either path.
This is not a permit calculation, a utility approval, or a substitute for a licensed electrician, HVAC contractor, or the authority having jurisdiction. Panel Headroom is an independent educational site. It is not a utility, a certification body, or a contractor. Electrical and generator work that is done incorrectly can cause fire, shock, or carbon monoxide poisoning. Use the adopted electrical code and manufacturer instructions; pull permits where required.