Skin tumors are abnormal growths on the skin that can be benign (non-cancerous) or malignant (cancerous). They can arise from various skin cells and may appear as moles, lumps, or lesions. Common types include basal cell carcinoma, squamous cell carcinoma, and melanoma. Factors such as sun exposure, genetics, and skin type can influence their development. Diagnosis typically involves a physical examination and may require a biopsy to determine the nature of the tumor. Treatment options vary based on the type and stage of the tumor and can include surgery, radiation therapy, or chemotherapy. Regular skin checks are important for early detection.