The common term that describes a beverage stopper or cap used to keep the liquid contents in bottles from being exposed to air or being allowed to flow out. During earlier times, many bottles used traditional wood Corks as bottle stoppers for whiskey, beer, rum, wine, other beverages, and medicines. However, as production methods have changed and as materials have evolved, the process of Corking bottles has become limited to only a few types of beverages. Today, a wood Cork is used in some liqueurs, many wines and most champagnes. Although wooden Cork materials are commonly used to make some bottle stoppers, other materials are being processed which include plastic, nylon, rubber, wood Cork, and synthetic materials that are manufactured into beverage Corks.