# What Firebase Is — Firebase

Source: https://www.skillbyai.com/en/firebase/fo-what

> Google's app development platform.

## A family of managed services

Firebase is Google's platform for building web and mobile apps without running your own servers. Core building blocks include **Authentication** (user sign-in), **Cloud Firestore** (a document database with realtime updates), the older **Realtime Database** (one large JSON tree), **Cloud Storage for Firebase** (files), **Cloud Functions for Firebase** (server-side code), and **Hosting** / **App Hosting** (web deploys). Around them sit app features such as Cloud Messaging, Remote Config, Analytics and Crashlytics. A Firebase project is also a Google Cloud project, so you can reach the same resources from Google Cloud tools. The product list and plan details change over time, so check the docs.

## A backend you call from the client

Firebase is a set of managed backend services that apps use directly through client SDKs, guarded by Security Rules.

![Three ideas: the product family, the client SDK model, project setup and config.](assets/figures/firebase/section-1-map.svg) — Figure 1.1 — Products, the client-to-backend model and project config.

## Which product for which job

Rules of thumb.

```text
sign users in                       -> Authentication
structured app data, queries        -> Cloud Firestore
simple low-latency synced state     -> Realtime Database
images, video, user uploads         -> Cloud Storage for Firebase
trusted server logic, webhooks, cron -> Cloud Functions for Firebase
static sites / SSR web apps         -> Hosting / App Hosting
push notifications                  -> Cloud Messaging (FCM)
feature flags, config changes       -> Remote Config
```

## A furnished office instead of an empty building

Firebase hands you rooms that already have plumbing (auth, database, files, hosting); you decorate them, but you accept the building's layout.

**Quiz:** Which Firebase product is a document database with realtime listeners and rich queries?

- [ ] Remote Config
- [ ] Cloud Messaging
- [x] Cloud Firestore
- [ ] Hosting

*Answer:* Cloud Firestore. Firestore stores documents in collections.