Everyone has a different skin complexion genetically determined largely by melanin content. To simplify the huge variation in the the different types of skin, all people are categorised into one of six Skin Types (based on the Fitzpatrik Phototype Scale).
Depending on your skin type, you have more or less natural Sun protection and susseptibility to sun-induced skin damage.
Poeple with lighter hair and fairer skin (therefore with a lower Skin Type value), are more at risk of developing both Basal Cell Carcinoma and cutaneous Malignant Melanoma (Elmets et al, 2001).
Knowledge of your Skin Type is vital in determining your safe period of sun exposure calculated with the UV Index for that day. It is also required to calculate how your safe period of sun exposure is extended with the applicable SPF (Sun Protection Factor) of the sunscreen that you are using.
Below is a diagram illustrating the charactereistic differences between each skin type, and possible genetic origins to help you determine your skin type.