It's your first introduction to the true military. They wake you up at oh dark stupid, and put you on a buss. You spend all day doing a series of basic medical examinations (eyes, hearing, blood test, ect). Then they make you duck walk in bare feet and underwear. Then they make you wait a while and pull you in to an office with a doctor who gives you a look over, tells you to drop your pants and cough, then has you bend over while your pants are down and grab your toes.
After that, it's off to boot camp