A modder is a person who modifies yo-yos for performance or aesthetic reasons. Modders often invent new modifications that push the sport of yo-yoing into new realms (e.g. recessing or siliconing). Modders will take a stock yo-yo and mod it to take the yo-yo to the next level of playability. Many of the now common advancements in yo-yo technology were first attempted and developed by modders. Some mods are executed for the sake of enhancement, while other mods are necessary to revive a broken or otherwise unfavorably configured yo-yo.