Melanocytic nevi, commonly known as moles, are benign growths on the skin that arise from melanocytes, the cells responsible for producing the pigment melanin. They can vary in color, size, and shape, often appearing as small brown or black spots. Most people have multiple nevi, which can develop during childhood and adolescence. These nevi are generally harmless, but changes in their appearance, such as asymmetry, irregular borders, or color variation, may indicate potential skin issues, including melanoma, a type of skin cancer. Regular skin checks are recommended to monitor any changes in existing moles.