There are only monorails running to the Magic Kingdom and to Epcot.
However there is a bus service that runs for free which can get you to the other parks, and there are boats which run on the lakes that can get you between resorts that have a jetty.

First off, if you bring your car you can drive to the parks. There are signs everywhere pointing you to where you need to go. This might not be the best suggestion thought, because parking can sometimes be far away from the parks, and not the easiest to find where you parked. If this is what you’re going to do, write down that number on the pole! Ive had troubles with this before.
For everything else, Disney Provides transportation. They have the buses, which go to almost all (if not all of the resorts) and go to every park, including the water parks and downtown Disney.
You can also take the monorail. Depending on what resort you’re staying at, it may come into it, or very near it. Sometimes, if you have dining at a certain hotel, you need to take the monorail to get there.
Boat- The boat goes to Magic Kingdom, the boardwalk and more. It’s beautiful and breezy.
My suggestion would be to take all the forms of transportation at least once, especially the monorail if you have little ones, because my little sisters loved that!

you would get to them by monorail. but if you want to change parks during the day, you would use the park hopper which you can purchase with your disney world package online. im going there on the 16 to the 23!!!

If you are staying at a disney hotel, you can hop on a bus to any of the 4 parks, 2 water parks, downtown disney, and back to your hotel. Its very simple, every disney hotel comes with a bus stop. As for monorails, that works for Magic Kingdom and Epcot, and you can also reach Hollywood Studios by ferry. But i recommend the bus.

The monorail runs to EPCOT and the Magic Kingdom. You can get to the other parks by taking the bus, which is free. And you can also get from EPCOT to the Disney Studios by taking the water ferry that picks up at the International Gate between the British and French pavilion.