How can I communicate between two activities in android?

Communicating activity and fragments

1. Step 1 — Define an interface in your fragment. You need to define an interface in your fragment class with all your listeners that your activity will need to implement as callbacks, like this: public class MyFragment extends ListFragment { …
2. Step 2 — Implement the interface. @Override.

How do you communicate between service and activity?

We know how much service are important in Android Application Development. We already know that we can communicate with Service from activity just by using method startService() and passing Intent to the argument in the method, or either we can use bindService() to bind the service to the activity with argument Intent.