Agreeing with others; the defining documentation is:
A). Do your ADSO (and perhaps a few additional years, but not enough to reach retirement threshold and nor receipt of benefits), resign and get out with no benefits nor retention of commission. You get a DD-214 which characterizes your service, and you're considered a veteran if certain basic criteria are met. You do not retain your officer title.
Or
B). Meet the published requirements for retirement eligibility. Receive retirement orders (not a DD-214) and a blue retiree ID card (technically a form DD-2). Enjoy lifetime benefits, such as pension, base/post privileges, medical, pharmacy, etc. Retain officer commission in retired status. Still on the personnel rolls, can be involuntarily recalled to active duty.