"Vestidos de quinceañera" means "dress of a girl turning fifteen." In Latino culture, a girl's fifteenth birthday marks her passage into womanhood, and girls usually wear fancy dresses for their fifteenth birthday celebration.
The word "quinceañera" comes from the Spanish words "quince," meaning "fifteen," and "año," meaning "year." The letter "a" at the end of the word signifies that it is feminine. The equivalent male word, "quinceañero," is uncommon because Latino boys do not usually hold large celebrations for their fifteenth birthdays.
Quinceañera celebrations involve both a church ceremony and a party. The girl usually wears a fancy dress and a crown to symbolize that she is a princess for the day. During the party, her father removes her sandals and puts high heels on her feet to show that she has become a woman.