what does flat-rate mean in shipping

what does flat-rate mean in shipping refers to a pricing structure where the cost of shipping is fixed, regardless of the size, weight, or destination of the package. Flat-rate shipping is often used by postal services and couriers to simplify the shipping process and provide customers with predictable shipping costs. For example, USPS offers flat-rate boxes where customers can ship items for the same price, no matter how much the box weighs, as long as it fits within the designated box size. This option is particularly useful for businesses that regularly ship items of similar size or weight.