Early Decision or ED is a binding contract for the candidate in that if he/she is admitted they must attend. All other applications which might have been filed must be withdrawn. Some colleges have ED I and ED II; both occur usually Nov/Dec/Jan. If the student is not admitted but deferred, the obligation to attend disappears and the application is placed in the regular pool to usually be reread and treated as a regular app.

Early Action or EA has the same early deadlines but there is no binding commitment to attend for the student. The college renders a decision and if admitted, the candidate simply has that one in the bag with no obligation to attend. A very few colleges have Single Choice Early Action or Restricted Early Action and that simply means a student may apply to only them on any early basis and not a slew of others. The no obligation rule still applies though. As with any early decision, deposits must be placed before May 1 to hold the spot---no college should require/request one before that date, unethical.

Rolling Admissions (the practice of many public institutions) means that beginning at a certain date in the fall, colleges will read applications which are complete on a continual basis until they fill. Obviously with Rolling Admissions, it pays to get your stuff in early in the cycle as once the spots are allotted, game's over.