In tracking the users’ behavior within an app, a straightforward way is to look at where they go and what they click. This approach is useful in identifying drop-offs and success rates in completing tasks. Apart from this, it’s important to establish context on a particular task. We must know where a user came from and where he or she is going, before and after completing the main task, respectively.
Entrance is the referrer or where the user came from. Main is the task flow. Exit is where the user went after completing the task.