Everyone's larynx grows during puberty, but a girl's larynx doesn't grow as much as a boy's does. That's why boys have Adam's apples. Most girls don't have Adam's apples, but some do.

The Adam's apple, in relation with the thyroid cartilage which forms it, helps protect the walls and the frontal part of the larynx, including the vocal cords (which are located directly behind it). Another function of the Adam's apple is related to the deepening of the voice.