Pajamas, also spelled pyjamas (see also spelling differences) and often shortened to PJs, can refer to several related types of clothing. The original paijama are loose, lightweight trousers fitted with drawstring waistbands and worn in South and West Asia by both sexes. In many English-speaking nations, 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, pajamas may refer to several garments, for both daywear and nightwear, derived from traditional pajamas and involving variations of style and material.