A high school dance is an event that is typically held at the end of the school year. It is usually attended by students in grades 9-12 and is a formal or semi-formal event. Two common types of high school dances are PROM and HOP. PROM is a formal dance that is usually held in the spring and is attended by couples or groups of friends. HOP is a less formal dance that is usually held in the fall and is attended by individuals or small groups.