A "payline", also often referred to as primarily a win line, is a line on the reels of a slot upon or along which symbols on the reels must line up in order to form a winning combination. Depending on the respective slot, there may be one or more paylines and the number of active paylines then determines how many ways a player can win in. When a winning combination is formed along a payline, the player is awarded a prize. Most modern slots have flexible paylines, meaning the player can set and adjust the number of active paylines.