Diapers are made of cloth or synthetic disposable materials. Cloth diapers are composed of layers of fabric such as cotton, hemp, bamboo or microfiber and can be washed. Disposable diapers contain absorbent chemicals and are thrown away after use. Plastic pants can be worn over diapers to avoid leaks, but with modern cloth diapers, this is no longer necessary.[citation needed]

Diapers are primarily worn by children who are not yet potty trained or experience bedwetting. However, they have also been used by adults with incontinence or in certain circumstances where access to a toilet is unavailable. These can include those of advanced age, individuals with certain types of physical or mental disability, and people working in extreme conditions, such as astronauts. It is not uncommon for people to wear diapers under dry suits.