How does the mechanism of data sending from the server differ from push notifications?

Sending data from the server and push notifications are different mechanisms:

• Sending data from the server: Usually involves client-initiated requests (e.g., via HTTP). The client initiates the connection and receives a response. The server cannot directly send data without a client request.

• Push notifications: A mechanism where the server can send messages to the user's device without a request. In Android, this is done via Firebase Cloud Messaging (FCM). Notifications arrive through a dedicated service, and the app can react to them even if not active.

The main difference is that push notifications allow the server to initiate communication and deliver information in real-time, whereas regular data sending requires a request from the client.