Does Firebase have a server?

Android, and the Web. Firebase provides detailed documentation and cross-platform SDKs to help you build and ship apps on Android, iOS, the web, C++, and Unity .

In this architecture, Firebase sits between the server and clients . Your servers can connect to Firebase and interact with the data just like any other client would. In other words, your server communicates with clients by manipulating data in Firebase.25 Mar 2013

Firebase Cloud Messaging (FCM), formerly known as Google Cloud Messaging (GCM), is a cross-platform cloud solution for messages and notifications for Android, iOS, and web applications , which as of 2021 can be used at no cost.