A colloquial phrase referring to the basics of a
job, task, or concept. Similar in use to "the nuts and bolts" or "the ins and outs". Interestingly, all three of these phrases contain
double entendres, but are intended for use in a generally non-
sexual manner.
Oh, you're new here? Let me show you the
balls and the butts of running the cash register.
Jesse, shut up. You really
don't understand the
balls and the butts of comedy.