Diapers are absorbent undergarments designed to be worn by babies, young children, and sometimes adults who are unable to control their bladder or bowel movements. They come in various sizes and styles, including disposable and cloth options. Disposable diapers are typically made of a plastic outer layer, an absorbent core, and an inner lining that wicks away moisture, while cloth diapers are made of soft, breathable materials that can be washed and reused.