Firebase Realtime Database Rules determine who has read and write access to your database, how your data is structured, and what indexes exist. These rules live on the Firebase servers and are enforced automatically at all times. Every read and write request will only be completed if your rules allow it. By default, your rules are set to allow only authenticated users full read and write access to your database. This is to protect your database from abuse until you have time to customize your rules or set up authentication.