Batter is a term for a thin, pourable dough. Generally, batter is used only for mixtures that are thin enough to fill their container completely, while "dough" is used for mixtures that are thick enough to hold some of their shape. The term is also used for thin pastes that are used as a coating for fried foods.
Batters are a common step in the preparation of:
A beer batter is a batter that is made using beer as the liquid; they are generally used only as coatings for fried foods, especially fish. A battered item is one that has been dipped in a batter prepatory to frying.