Sync or Stink: Why Some Apps Can't Handle Mobile Data | MongoDB Blog` MongoDB Realm eliminates the complexity of building a sync tool that works in an offline-first environment, like mobile, by providing pre-built conflict resolution out of the box. This allows development teams to focus on delivering competitive differentiation instead of worrying about complicated data sync and conflict resolution tools. The Realm Mobile Database is object-oriented, making it intuitive for mobile developers, while Realm Sync synchronizes data bi-directionally between the Realm Mobile Database on the client and MongoDB Atlas on the back end. By using Realm, development teams can speed up development and turn around feature requests faster, resulting in better app experiences and user satisfaction.