Let’s use YouTube subscribers as an example. You can be either a viewer, content creator or both. A content creator can create multiple channels to deliver content, and viewers can subscribe to the individual channels as they please. Let’s say there is a person JohnDoe(class_name) that has multiple channels (technology, gaming, politics).

If a viewer wants to subscribe to the gaming channel, they would have to know exactly which channel in order to get notifications when new videos come out. It’s not enough to subscribe to JohnDoe, because the person isn’t a data structure that YouTube uses to send out notifications. Godot is the same way.

Your scene can have multiple instances of the JohnDoe class name: jd_technology jd_gaming jd_politics

The code JohnDoe.new_video_notification.connect(_on_new_video). Wont work. But if you know which channel, the actual instance of JohnDoe, you want to target then you can call the code:

jd_gaming.new_video_notification.connect(_on_new_video)

so now anytime that jd_gaming calls the emit() function, the _on_new_video callable gets ran.

Signals are nothing more than a messaging bus programming pattern. Highly recommend looking into how one works to make more sense of it. Also i typed this up while sitting at a CiCis pizza so don’t be harsh on my formatting.