The most prevalent reason for getting skin cancer is prolonged exposure to the sun. But, it is not the only cause. Various factors such as family history, weak immune system, and exposure to harmful radiation can have a lead role in developing cancer. Although, sometimes the reasons are unknown. Simply put, skin cancer is the irregular growth of skin cells. This results from an error in the skin cell's DNA, leading to abnormal development. But, the good news is that almost all types of skin cancers are treatable. They are mainly three types of skin cancer- Basal cell skin cancer, Squamous cell skin cancer, and Melanoma. Merkel cell skin cancer, Kaposi sarcoma, and lymphoma are some of the rare types of skin cancer. Basal cell skin cancer, squamous cell skin cancer, and other rare skin cancer are also called non-melanoma cancer.