The term Vintner's Vessel is composed of three words: VAT, TUN, and VISAS. A VAT is a large container used to store liquids, such as wine, beer, or cider. A TUN is a large cask or barrel, usually made of wood, that is used to store and age wine. VISAS is an acronym for Vintners International Standards and Approvals System, which is a set of standards and regulations that govern the production and sale of wine. Together, these three words form the term Vintner's Vessel, which refers to the containers and systems used by vintners to produce and store wine.