A muffin tin, also called a muffin pan or cupcake tin, is a baking pan with a row of cup-shaped wells, usually 6 or 12, that hold batter for muffins, cupcakes, and other individually portioned baked goods.
Pans are most often metal (aluminum or steel, frequently nonstick-coated), though silicone versions are also common; wells are typically round and vary in depth, from shallow cups for flat muffins to deeper wells for tall, domed ones.
Beyond muffins and cupcakes, a muffin tin is a convenient way to bake individual portions of other dishes, such as mini quiches, frittatas, baked eggs, or mini pies, since the separate wells keep servings the same size and let them cook evenly.