Firebase is a developer toolbox that provides tools to help build apps including a real-time database, authentication, storage, remote config, and analytics. The real-time database allows for real-time syncing of data across clients. Firebase also provides user authentication through supported sign-in methods. Firebase Analytics automatically captures usage data that can be used to understand user behavior and improve apps. It also allows developers to define custom events. The tools in Firebase help developers better understand users to create extraordinary apps.