What is Firebase and what is it used for in an application?

Published on 2026-10-17 by frfrand

Firebase de Google explicado desde cero: autenticación, Firestore, alojamiento y funciones, con ejemplos y limitaciones reales.

Do you want to create an appointments app. You already have the screens, but you still need to know who logged in, where to store reservations, and how to make changes appear on other devices. You could build all of that from scratch. Firebase is a set of Google services for developing and operating applications, especially useful when you want to solve several of those needs without managing all the infrastructure yourself.

It is not a single database, nor a programming language nor a virtual machine. It is a platform with different products.

What can Firebase do?

Authentication: allows managing logins with different methods. Having an identified user is the beginning, but then you have to decide what data they have permission to query.

Cloud Firestore: is a NoSQL database that organizes information into documents and collections. It can be convenient when your application's model fits that structure.

Realtime Database: another Firebase database, designed for real-time synchronization, with a different model than Firestore.

Cloud Storage: is used to store files, such as photos, documents, and videos, with rules to control access.

Hosting and App Hosting: offer options to publish web applications. Not all have the same features or admit exactly the same projects.

Cloud Functions: allows executing backend functions in response to events or requests without personally managing a traditional server.

The platform has more products, but with these you already understand its central idea.

An example: a reservation application

A user opens an app to book a yoga class. They register using Authentication, check schedules stored in a database, and submit their reservation.

The app can update available schedules for other people when data changes. If the user uploads a photo, the file can be stored in Storage.

This does not mean that all these pieces activate automatically when creating the project. You have to design the information model, permissions, rules, and business logic.

Does Firebase replace a backend?

It can replace part of a backend's work, but not necessarily everything. A simple application can solve authentication and data access directly with SDKs and security rules.

On the other hand, if you manage payments, complex operations, or decisions that require delicate validations, you will likely need server functions or your own backend. The platform offers services to combine both approaches.

A common trap is thinking that because you use a managed service, you no longer need to design security. Access rules are an essential part of the work.

What is the difference with PostgreSQL?

Firestore uses documents and collections instead of the typical relational model of PostgreSQL. This affects how you represent relationships, perform queries, and organize information.

It does not mean that SQL is outdated or that NoSQL is automatically faster. It depends on the data and the queries you need. Additionally, the Firebase ecosystem has incorporated services that connect with relational databases, so it is worth evaluating each specific product and not reducing the entire platform to a single database.

Is Firebase free?

There are free-to-use options and billing plans based on products and consumption, subject to limits and conditions that may change. Before launching a real app, check quotas, read/write operations, transfer, storage, and additional services in the official documentation.

A small prototype and an application with thousands of users can have very different spending patterns.

What does it have to do with ArduMaker?

ArduMaker allows you to manage server environments and databases, an architectural alternative when you prefer to keep more components under your control. This does not make Firebase a bad option: they simply solve parts of the problem differently.

In one sentence: Firebase is a toolbox for building applications without having to implement or manage every backend component yourself.

More information: Official Firebase Products.