2 answers
Schools have so many different names for the same program, but let me explain the few I know.
Early Action is not binding. This means you do not have to go if you are accepted. You can apply to ten million schools under early action, if you wish.
Restrictive Early Action is practiced by schools such as Yale, Harvard, and Princeton. It is not binding. However, you cannot apply to another private university or college under their own early program. But get this: you can apply to a state university under its early action program because it is not a private school.
To illustrate: I can apply to Yale under its REA program, and to Arizona State University under its Early Action program. But I cannot apply to Yale under REA and apply to the Minerva Schools (a private school) under its EA.
Third: Single Choice Early Action. It is practiced by Stanford. It is not binding. But you cannot apply to any other school, whether public or private.
I urge you to look up the website of the school you want to apply to and see its policies. Good luck.