Warts are harmless skin growths caused by human papillomavirus (HPV). They appear anywhere on the body but are most common on the hands, feet, and nails. Warts are typically rough and may appear as a single bump or in clusters. While they are generally harmless, warts can be contagious and may spread to other parts of the body or other people through direct contact. Treatment options include over-the-counter salicylic acid preparations, cryotherapy (freezing the wart with liquid nitrogen), and more advanced procedures like laser therapy or surgical removal, depending on the wart’s size, location, and resistance to previous treatments.