A lot of people are a mix, oilier through the T-zone across the forehead, nose and chin, and drier on the cheeks. That combination usually sits close to balanced. If one tendency is clearly stronger than the other, lean that way, and remember you can always treat a particular area differently, which is what the note at the end covers.
Question two: does your skin react?
The second question is whether your skin is reactive, and it's the one people most often get wrong, because almost everyone feels their skin is a little sensitive. So set the feeling aside and look for the signs instead.
Reactive skin tends to sting or prickle when you try something new, before it settles, if it settles at all. It reddens or goes blotchy easily, in cold wind, after a hot shower, or for no obvious reason. It can feel tight, itchy or rough, and it reacts in situations where most skin wouldn't. If several of those ring true and they happen often rather than once in a blue moon, your skin is probably on the sensitive side. If new products generally sit fine and your skin stays fairly even, it probably isn't.
Reactivity mostly shows up at the two ends of the spectrum, with dry or oily skin, rather than in the calm middle. Balanced skin that reacts strongly is genuinely uncommon.
Two answers, then. Where you sit from dry to oily, and whether your skin reacts. Together they point to one of five types.