Is it true that our military is an all volunteer to sign up for the military?

The reason I ask, is I was in my local Post Office recently, and saw the cards for Selective Service Registry. Are the men in the USA still required by law to sign up in the Registry? How does that work? Thanks for the answers!

If you are a man between the ages of 18-25, then you must register for selective service. It is required by law. Make sure to register before your 26th birthday or its to late. Even though you register, does not mean you are signing up for the military. If a crisis occurs that requires a Draft, men are called up in sequence determined by random lottery number and date of birth. If you are in the military (active duty), you are not required to register because well you are already serving your time; however, if a man leaves the military before he turns 26 he is required to register.
The military is all voluntary though!

To do the selective service thing , you just pick up the card from the Post Office, fill it out and return it to them.That is all you have to do with that. The military is all-volunteer, all you need to join is a diploma or a GED. You must pass the asvab and the physical, sign all your paperwork and off you go!

Yes the military is volunteer.

Selective service is a just formality. It is for the draft IF there ever was one, and there hasn't been for many many years. It allows you to get government jobs and student aid. No reason not to do it and I believe its illegal not to do so.