As clarkfamily says it depends where you have seen it. Disney themselves have some kind of rating system but its a few years since I was told about it, never see it talked about. It is something like 1st level open to everyone, next level they stop offsite guests, next they stop AP holders, next DVC members etc.....
It's called phased closing and it looks like this :
Phase 1
Guests with 'Magic Your Way' base tickets, or a '1-Day 1-Park Ticket', Guests without an admission ticket, and Cast Members using Main Gate & Silver Passes will be turned around at the parking lot booths.
Phase 2
Admission is limited to:
Disney Resort Guests (including the Walt Disney World Swan and Dolphin, and guests arriving by bus from the Hotel Plaza Boulevard hotels)
Annual and Premium Annual Passholders
Guests with Hopper tickets coming from another park
Guests re-entering the park
Guests with dining reservations
Magic Kingdom Guests with reservations for Bibbidi Bobbidi Boutique or The Pirates League
Guests using Walt Disney World Resort Transportation will be admitted.
Phase 3
Admission is limited to:
Disney Resort Guests (including the Walt Disney World Swan and Dolphin, and guests arriving by bus from the Hotel Plaza Boulevard hotels)
Annual and Premium Annual Passholders
Guests with dining reservations
Magic Kingdom Guests with reservations for Bibbidi Bobbidi Boutique or The Pirates League
Phase 4
Closed to all guests.