Yes, and flight specific typically, maybe it depends on airline, but at least generally it's not like a permanent ticket that gets you through to the gates for

Yes, and flight specific typically, maybe it depends on airline, but at least generally it's not like a permanent ticket that gets you through to the gates for any flight, you still 'book', you just can't necessarily get a seat or boarding pass until the last minute at the gate (at check-in if it's quieter).