Homecoming is a dance held in the fall, usually in October or November. It is typically held to welcome back students who have graduated from the school and to celebrate the school year. Homecoming dances often have a theme, and students may dress up in costumes. There is also usually a homecoming football game before the dance.
Prom is a dance held in the spring, usually in May or June. It is typically the last dance of the school year, and it is considered to be a formal event. Students typically wear formal attire, such as gowns and tuxedos. Prom dances often have a theme as well, and there may be a prom king and queen crowned at the dance.
So, while homecoming and prom are both high school dances, they are not the same thing. Homecoming is a more casual event held in the fall, while prom is a more formal event held in the spring.