According to Wikipedia, Pajamas, or pyjamas (British English), often shortened to PJs, jimmies, jimjams or jammies, 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 tailored for kids. More generally, pyjamas may refer to several garments, for both daywear and nightwear, derived from traditional pyjamas and involving variations of style and material.
For kids, there are a lot of choices of pyjamas that tailored specially for them. This including designs, styles, materials and practicality.