A Kodi addon provides specific functionalities like streaming content. It allows you to watch sport, movies, live TV, cartoons, and more. You can easily download and install these addons from both the official Kodi repository and third-party repositories. For example, you can download the MLB.TV addon to stream sports live. A repository is a storage location that houses addons, plugins, and software components for the Kodi media player. You can browse and install these addons to make Kodi better, like getting streaming services or media libraries. Official and unofficial repositories exist, but it's important to use them responsibly and respect copyright laws. A build is a pre-configured version of Kodi that includes multiple addons, skins, and settings. It provides an easy way of setting up a customized Kodi on your preferred device. However, you need to be careful as most builds come loaded with malware. Others will even impact the performance of your device.