burns are classified into 3 different groups
in a 1st degree burn, it is considered mild, and will only cause pain and reddening.
in a 2nd degree burn, it would cause pain, redness, swelling, and blistering, and affects the epidermis and dermis.
in a 3rd degree burn, the burn goes through the upper layers and affects the deeper tissues, resulting in white or blackened, charred, numb skin.
hope this helps