This page is archived and might not reflect the latest version of the FlutterFire plugins. You can find the latest information on firebase.google.com:
The Firebase Realtime Database is a cloud-hosted database. Data is stored as JSON and synchronized in realtime to every connected client. When you build cross-platform apps Flutter & Firebase, all of your clients can share one Realtime Database instance and automatically receive updates with the newest data.
View the Getting started guide.