An "Add-On" refers to a supplementary component or feature that enhances the functionality of a primary product or service. Commonly used in software, add-ons can provide additional tools, features, or capabilities that are not included in the original package. For example, a web browser like Google Chrome allows users to install add-ons to improve their browsing experience, such as ad blockers or password managers. In the context of gaming, add-ons can refer to downloadable content (DLC) that expands a game with new levels, characters, or storylines. This allows players to enjoy new experiences without purchasing an entirely new game. Popular games like The Sims often release add-ons to keep the gameplay fresh and engaging.