There are four main types — normal, dry, oily and combination — and, independently, skin may be sensitivity-prone. A simple test: cleanse gently, wait 1–2 hours with no products. Tight and flaky all over suggests dry; a shiny T-zone with normal cheeks suggests combination; shine everywhere suggests oily.
Skin type isn't fixed — season, age, hormones and products all shift it. For a precise assessment, consult a dermatologist.