Pajamas, or pyjamas, often shortened to PJs, can refer to several related types of clothing. Pajamas are loose-fitting, two-piece garments derived from the original garment and worn chiefly for sleeping, but sometimes also for lounging, also by both sexes. More generally, pyjamas may refer to several garments, for both daywear and nightwear, derived from traditional pyjamas and involving variations of style and material.
Traditional pajamas consist of a jacket-and-pants combination made of soft fabric, such as flannel or lightweight cotton.
Contemporary pajamas are derived from traditional pajamas. There are many variations in style such as short sleeve pajamas, pajama bottomsof varying length, or, on occasion, one-piece pajamas, and pajamas incorporating various materials.
Pajamas may today refer to women's combination daywear, they became popular in the early 20th century, consisting of short-sleeved or sleeveless blouses and lightweight pants.