Cosmetology by definition is the study of beauty and beauty treatment. It is divided into various specialties, there are those who deal with nail care. Others deal with hairstyles and haircutting. To become a cosmetologist one requires training and license. First I will talk about the length of cosmetology school. The length of cosmetology school depends on three factors: which beauty program you enroll in, your state's required hours for that program, and whether you enroll as a part or full time