A hairdo is a HAIRSTYLE that is created by styling the hair in a particular way. Common hairdos include a perm, which is a chemical treatment that permanently changes the structure of the hair; a STYLE, which is a temporary change to the hair; an AFRO, which is a HAIRSTYLE characterized by a mass of tight curls; a BUN, which is a HAIRSTYLE where the hair is gathered and secured at the back of the head; a COIFFURE, which is an elaborate HAIRSTYLE; a COIF, which is a close-fitting cap or hood for the head; a shag, which is a HAIRSTYLE with layers of different lengths; a SET, which is a HAIRSTYLE where the hair is combed and dried in a particular shape; a BRAID, which is a HAIRSTYLE where the hair is interlaced in three or more strands; a PONYTAIL, which is a HAIRSTYLE where the hair is pulled back and secured at the back of the head; RINGLETS, which are small curls; and a spitcurl, which is a small curl of hair.