Depends on what type of ticket you bought.
If you pay additional for the hopper to go from park to park..We paid 181.00. We started at Hollywood Studios , Epcot, Animal Kingdom then Magic Kingdom, all by shuttle buses that ran every 20 mintues.
You have to have park to park tickets to travel between Universal and Island of Adventure. If you do not have park to park tickets you have to stay in the park you paid for
You have to have the two park tickets (universal + islands of adventure)
No a train takes you and links the 2 or just walk
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