The "frozen" button on a toaster is a special feature that allows you to toast frozen bread, waffles, or other frozen food items without having to defrost them first. When you press the "frozen" button, it adjusts the toasting settings to accommodate the lower temperature of the frozen food.
Toasters with a "frozen" button typically have a built-in sensor or algorithm that adjusts the toasting time and temperature to ensure that the frozen item is properly toasted without burning or undercooking it. It may extend the toasting time to compensate for the frozen state of the food.
Without the "frozen" button, toasting frozen items would often result in uneven toasting or an exterior that is too crispy while the interior remains cold. The "frozen" setting helps to produce more consistent and satisfactory results when toasting items straight from the freezer.