This blog is from the Android development perspective. Realm is an open source NoSQL multi platform database. It’s simplicity and transaction speed has made it a very popular database for mobile applications. From the perspective of the end-users, Realm provides many appreciated features. Realtime functionalities and offline experience are faster and easier to build. SIMPLICITY A class will be bound to Realm database by extending from RealmObject. No need to tag the attributes, Realm will do the code generation for you.