Firebase is a Backend-as-a-Service (BaaS) that is part of the Google Cloud Platform. One of the most popular services of Firebase is the Realtime Database, which uses a WebSocket to sync your data. Firebase also offers services for file storage, authentication (social media and email/password authentication), hosting, and more.
You can use Firebase mainly for real-time applications, but you can also use it as your regular database for non-real-time applications if you want to. Firebase is supported by many languages (such as JavaScript, Java, Python, and Go) and platforms such as Android, iOS, and the web.
Firebase is free but, of course, if you need more capacity, they have different plans depending on your project's requirements. You can check out the prices at https://firebase.google.com/pricing.
For this recipe, we are going to use...