Final answer:
A first-degree burn is characterized by redness and affects only the epidermis. It is a superficial burn that typically heals on its own within a few days.
Step-by-step explanation:
A first-degree burn is characterized by redness. It is a superficial burn that affects only the epidermis. Examples of first-degree burns include mild sunburn, where the skin becomes red and swollen. These burns typically heal on their own within a few days.