The term 'washing vessel' can refer to two different items: a BASIN and a bathtub. A BASIN is a shallow, round container used for washing hands or other items. It typically has a wide rim and is made of ceramic, metal, or plastic. A bathtub is a large, deep container used for bathing. It is usually made of porcelain-coated cast iron, acrylic, or fiberglass. Both the BASIN and the bathtub are essential items in any bathroom.