Our nightly skin-care routine goes a little something like this: Remove makeup, cleanse, apply toner, moisturize and say a little prayer that we’ll wake up as glowy as Jennifer Aniston in a SmartWater commercial. But unlike the cleansing and moisturizing steps, we’re not always sure about the purpose of toner—we just swipe it on. So in the interest of skin-care schooling, here’s what toner does and why everyone needs it.