What does rated R movies mean?

Answer 1

R --"Restricted. Under 17 Requires Accompanying Parent or Adult Guardian": The Rating Board applies this rating to movies the members believe contain a high level of adult content, such as harsh profanity, intense violence, explicit sexual content and extensive drug use. In some states, the minimum age to see an R rated movie unaccompanied is 18.

This mainly applies to theaters i watched R rated when i was a kid at home with my older sister or parents some people wait for a movie to come out on DVD these in my day as a child it was video and boy did i see some Horror some were video nasties as they were called in the early 80's most people will wait til it comes out on DVD then show it in the privacy of their own home regardless of the rating as long as an adult is present.

Answer 2

It means the movies are "Restricted" and only an adult, or child younger than 18 accompanied by an adult, can get in.