Article snapshot taken from Wikipedia with creative commons attribution-sharealike license.
Give it a read and then ask your questions in the chat.
We can research this topic together.
Device for serving and preserving wine
Wine dispensers are devices designed to serve and preserve wines. Dispensers store stored wines at cool temperatures and oxygen is prevented from entering the bottle when pouring. Wine dispensers vary greatly in use and function, most commonly wine dispensers are used in restaurants and bars to prevent spoilage when selling wine by the glass. The dispenser has the additional benefits of controlling the amount of the pour limiting over-pour.