What is a military draft?

compulsory enlistment of people in a national service, most often a military service. Conscription dates back to antiquity and continues in some countries to the present day under various names.

A system for selecting young men for compulsory military service, administered in the United States by the Selective Service System. At present the United States relies on a volunteer military and does not have a draft, though young men are required by law to register with the Selective Service.