EA = Early Action. If you apply by the EA deadline you will get a decision early. It is not binding. You can choose to go there or not. The benefit of EA is that you know earlier than with the RD deadlines. Also, it shows interest. Not every school has an EA option, though.
ED= Early Decision. If you get accepted, you must withdraw all your other applications and you must attend that school.
Early Decision (ED) - Can only apply to that college binding contract with the university saying you must go there when you get in. You get to know whether you get in or not to a university earlier with an earlier application deadline.
Early Action (EA) - Not binding, can apply to multiple colleges, basically, RD but applications are due earlier, and an earlier response from the universities too. If you get in, you can choose whether you want to go or not. There is a smaller pool of applicants during this time.
Overall difference: EA is applying early to the school with a smaller pool of applications and having the choice of whether you want to go there or not depending on if you’re admitted. ED is applying early to a school and committing to it saying you have to go there if you get accepted (a contract).