An overlay in League of Legends is a graphical user interface (GUI) element that is displayed over the game client. Overlays can provide a variety of information to players, such as champion stats, item builds, and minimap awareness. Many overlays are also customizable, allowing players to tailor them to their own preferences. Well-designed overlays can give players a significant advantage in-game, by providing them with easy access to important information.
There are many different overlays available for League of Legends, and the best one for you will depend on your individual needs and preferences. Some of the most popular overlays include: