answer 1
Different skintypes mean the balance of oil and water in your skin. Most companies offer 3 different formulas: one for dry skin, one for "normal" skin and one for oilier skin. Clinique differentiates between 4 skin types. Skintype 1 is a very dry skin. Skin feels dry everywhere and all the time. Skintype 2 means the cheeks feel mostly dry and you are likely to get a bit of shine in the t-zone. A skintype 3 would describe the cheeks as comfortable or normal, and there definitely is some shine in the t-zone. Skintype 4 is an oily skin, never feels dry, constantly needs to powder.
Often the skintype varies due to weather conditions, e.g. you could be a skintype 3 in summer, but a 2 in winter. Hope, this helps!