Burns can result from exposure to heat, chemicals, electricity, or radiation, causing damage to the skin and underlying tissues. The severity of a burn is categorized into degrees, with first-degree burns affecting the outer layer of skin, second-degree burns affecting the outer and underlying layer, and third-degree burns extending into deeper tissues. Immediate care involves cooling the burn with running water and covering it loosely with a clean cloth. Severe burns require medical attention, and proper wound care and rehabilitation are crucial for recovery and prevention of complications.