What is the difference between 1st degree and 2nd degree burns?

Blisters, pain: 1st-degree burn: least serious. It burns only the outer layer of skin. The skin turns red, may see swelling, pain mild. 2nd-degree burn: the burn is deeper, blisters develop, skin is usually very red, swelling occurs, pain more severe. 3rd-degree burn: most serious burns, it involves all layers of the skin. It causes permanent tissue damage. Fat, muscle and even bone can be involved.