What is a Semi-formal high school dance ? What is the difference between a semi-

Question:And tell me why do we need to dress formal or semi-formal

Best Answer - Chosen by Asker: And tell me why do we need to dress formal or semi-formal

Prom has always been the suit and tie and some sort of clingy formal or ball gown: because this is usually an event that the crowning of students take place and represent their prestige in school. Semi-formal is more the skirt and nice shirt or even nice dress slacks and a sweater/shirt maybe even a jacket to top it off. Men can wear dockers and a nice shirt or even t-shirts.

It's a dressier event than everyday clothes but not formal enough to wear gowns/tuxedos. You can wear a nice dress or skirt/blouse for the gals or for the guys shirt & tie/suit.

A casual/short(er) dress for the girls is often just fine for a semi-formal while a prom requires a long dress and extensively styled hair. Guys, for prom it's a tux, and for a semi-formal dress pants, dress shirt, and maybe a tie.
I have no idea why there's formal or semi-formal, blame the early 20th century. And have fun at your dance.