For each day of your trip you can select an arrival window for up to 3 experiences. You can modify your selections as well. Once you redeem a multi pass experience (i.e. ride the ride) you can make another selection and have up to 3 passes at any given time. If you have the Park Hopper Option for your ticket you can make selections in another Walt Disney World theme park after you have used your first pass. Each park has multiple tiers of experiences and you can only choose one out of your 3 to be from tier 1. Make sure to look at which experiences are in each tier at each park, this does change often. You pay one price to use multi-pass all day.

Each park has a few top experiences that are not available on Multi-pass, instead they are only available as a single pass. You select an arrival window for that experience just like you do for each experience in the multi-pass. You can purchase only one single pass per experience and you pay based on the experience and demand for that attraction. 

​You purchase Premier Pass for a single park per day and you can use it on any experience that has a Lightening Lane without selecting an arrival window. You can only use the pass one time on each experience for that day.