AP Early Entry Registration

[BarTopDancer]

It sounds like it works like early entry for people who stay onsite in Disney hotel rooms. You can enter the park an hour earlier than the general public and get on some rides, or get in line an hour before everyone else who isn't staying on site or registered for the AP day (aka the general public).

That's all, you don't hang out for an hour then get booted out of the park, you just get in an hour before the general public can. It's been a perk of getting hotel rooms at DLR or WDW for years.