Realm
Realm is a mobile database designed for real-time, offline-first applications, offering an object-oriented data model with automatic synchronization capabilities. It provides a fast, lightweight alternative to SQLite and Core Data, with built-in support for reactive programming patterns. Realm is primarily used in mobile development for iOS, Android, and cross-platform frameworks like React Native and Flutter.
Developers should learn Realm when building mobile apps that require high-performance local data storage with real-time updates, such as chat applications, collaborative tools, or offline-capable apps. It's particularly useful for scenarios where complex object relationships need to be managed efficiently without manual SQL queries, and when seamless synchronization with a backend (via Realm Sync) is needed for multi-user experiences.