Wine cellars are used to protect wines from external influences such as heat, light, vibration or fluctuations in temperature and humidity.  Because wine is a natural, perishable product, all types of wine can spoil.  Proper storage of wine helps maintain the integrity and in many cases will improve the aroma, flavor and complexity of the wine as it matures.

A wine cellar is simply a storage room for wine.  Wine cellars are traditionally depicted as large underground lairs built to reduce variances in temperature; these are usually not temperature controlled and are referred to as passive wine cellars.  An active wine cellar is a system which provides climate control where both temperature and humidity are maintained at a constant level.

A wine cellar which is located aboveground is often called a wine room.  A small wine cellar which holds less than 500 bottles is usually referred to as a wine closet.  Obviously many wine enthusiasts lack the space to devote an entire room or closet in their house and build a temperature controlled climate which makes solutions like a wine cooler or wine refrigerator an affordable solution.