firebase Database Rules
Introduction
With Firebase Realtime Database, your Database rules is your server side security. You need to be very careful and aware of who has access to your database. It is important that no one gains access to your data that shouldn't.
By default, the Firebase Realtime Database rules allow any authenticated user to read and write all the data, this is probably not what you want your app to do.
Take a look at the below examples for different scenarios.
Remarks
The Firebase Realtime Database provides a flexible, expression-based rules language with JavaScript-like syntax to easily define how your data should be structured, how it should be indexed, and when your data can be read from and written to. Combined with our authentication services, you can define who has access to what data and protect your users' personal information from unauthorized access.
By default, your database rules require Firebase Authentication and grant full read and write permissions only to authenticated users. The default rules ensure your database isn't accessible by just anyone before you get a chance to configure i
Official Documentation
https://firebase.google.com/docs/database/security/quickstart
