There are two main kinds of tofu silken and regular.  Silken tofu- known as soft, silk, or Japanese-style tofu. It has a softer consistency than regular tofu and will easily fall apart if not handled carefully. It doesn't require refrigeration which is why is often found in a different section of grocery stores as opposed to regular tofu, which is packed in water and requires refrigeration. Best to use for making creamy sauces. Both silken and regular tofu can be found in soft, medium, firm, and extra-firm consistencies. They are made with the same ingredients, but they are processed differently to a small degree which is why they are not interchangeable in a recipe.