I believe you mean Quinceñera, and the difference if just that a sweet sixteen is for people turning 16, and its basically just a party. In the mexican culture a quinceñera is a celebration revolving around a 15 year old girl. It's a big step from being a little girl to a women. Some of the stuff that people do are give them a porcelain doll as a symbol of showing how that doll is the last doll they'll receive. Another thing they do is change the shoes, for example the girl is supposed to come in with flats so then either both of her parents or just one change the flats into high heels. Then last but not least the father-daughter dance.