They are not the same, but ghost kitchens do operate out of a commissary. A commissary is a shared use kitchen. A ghost kitchen (which admittedly would probably be better called a ghost restaurant) is basically just a delivery/pickup-only restaurant. It may operate out of a commissary or its own space.

The Food Corridor is a (very terrible) piece of software that allows bookings for kitchen space, so they probably focus on the ones that work from public kitchens for that reason, but lots of them have dedicated kitchens or rent from a church hall or VFW.