Povidone-iodine is a broad-spectrum antiseptic used for skin disinfection before/after surgery, treating minor wounds, and preventing infections, acting by releasing free iodine to rapidly kill bacteria, viruses, fungi, and spores. It is commonly used as a solution, swab, or ointment. While generally safe, side effects include skin irritation, rare allergic reactions, and potential thyroid dysfunction with prolonged, widespread use.