What is the advantage of Realm?

Should I use Realm or Core Data?

Core Data is incredibly fast if you consider what it does under the hood to do its magic. But Realm is faster, much faster. Realm was built with performance in mind and that shows. As Marcus Zarra once said in a presentation, you don't choose Core Data for its speed.

Why Realm is faster than SQLite?

Realm is designed for mobile from the get-go that uses and therefore makes trade-offs that make sense in the mobile platform whereas SQLite is a generic solution that was ported to mobile.

Can I use Realm for free?

Yes definitely you can use Realm for free to save unlimited data locally. Realm is only charging for cloud storage .

How does realm database work?

Realm offers Network Reliability: The Realm database is offline-first. It means that you always read from and write to the local database and not over the network. When the Realm Sync is enabled, the Realm Database synchronizes data with MongoDB Realm over the network in a background thread.