Melanomas are a type of skin cancer that develops from melanocytes, the cells responsible for producing the pigment melanin. They often appear as new or changing moles, and can vary in color, size, and shape. Early detection is crucial, as melanomas can spread to other parts of the body if not treated promptly. Risk factors for developing melanomas include excessive exposure to ultraviolet (UV) radiation, having a fair skin type, and a family history of skin cancer. Regular skin checks and awareness of changes in moles can help in identifying melanomas early, improving treatment outcomes.