What is the main difference between unsalted and salted butter?

The main difference between unsalted and salted butter is that salted butter contains added salt. Salt is used in butter primarily for flavor enhancement and acts as a preservative to extend the shelf life of the product. This means that when using salted butter in cooking or baking, it can affect the overall flavor and the necessary amount of seasoning in a recipe.

In contrast, unsalted butter allows for greater control over the seasoning in dishes since it does not contain added salt. This characteristic makes unsalted butter a preferred choice in baking, where precise measurements of salt can significantly impact the final product.

While other options touch upon different properties of butter, they don't specifically highlight the primary distinction in terms of added ingredients.