How does the Observer pattern ensure tracking changes in related objects?

The Observer pattern implements a subscription mechanism where one object (Subject) maintains a list of dependent objects (Observers) and notifies them of changes in its state. When the Subject's state changes, it calls the update method on all subscribers, allowing them to react to changes without tight coupling between objects. In Android, this is often used, for example, with LiveData, where UI components subscribe to data and automatically update when it changes.