Cosmetology is the study and application of beauty treatment. Branches of specialty including hairstyling, skin care, cosmetics, manicures/pedicures, and electrology.A hair stylist specializes in the styling of hair, including cutting and chemical services such as relaxers, texturizers, perms, and color, as well as restorative treatments. Such as scalp treatment to cure dandruff. They also use various of irons, rollers, and straighteners to do styles. Almost all states in the United States license hair stylist as cosmetologists which gives them the availability to perform any service that can be performed under state guidelines on hair, skin and nails.