Knowing your skin type is crucial, especially as that determines how you take care of it. From the products you use to possible solutions for skin problems, knowing one's skin type should be like knowing your blood type. Very, very important!
Combination/normal skin
The T-zone (the central part of the face, forehead and chin) is oilier in varying degrees, while the cheeks are drier. Ideally you would need to treat these two areas separately.