Panty liners are thinner and smaller than regular pads. They are used to absorb wetness and protect you from normal vaginal discharge. Pads are made specifically for the use of absorbing menstrual flow and are thicker than panty liners. There are different sizes of pads to help with heavier or lighter flowing periods. While pads are used during the menstrual cycle, panty liners are more often used at any time.