EA== Early Action, not biding, deadline around 11/1 and got notified around 12/15. You need to make decision around May 1 if you are accected by more than one college: Ex. MIT
SCEA== Single Choice Early Action, not biding, but you can only apply one college early, no limits on regular application, deadline around 11/1 and got notified around 12/15. You need to make decision around May 1 if you are accected by more than one college. Ex: Stanford,Yale.
By the way, both Harvard and Princeton eliminated early action a couple of years ago.