Non-melanomas are the most common type of skin cancer. They include basal cell carcinomas and squamous cell carcinomas. There are other types of non-melanomas, but basal cell and squamous cell account for the largest amount of non-melanomas. 

Basal cell carcinomas comprise eight out of 10 cases of non-melanomas and usually show up in areas where there has been a lot of sun exposure. Squamous cell carcinoma accounts for about two in 10 cases of non-melanoma and appears on sun-exposed skin. It also can appear in scars or chronic skin sores. 

Be sure to check with a dermatologist if you find any troublesome spots. Remember, skin cancer often can be cured if detected and treated early. Now that you have a baseline, do some exploring and be on the lookout for the differences between moles and skin cancer.