title: Why and When an android application has multiple tasks?
body: <p>Activities in an android application arranged in a task back stack.<br>When we use a single task launch mode for an activity then it can only belong to one task throughout all tasks in the app.<br>It's vague to me why an application may or should has multiple tasks?
  <br>I saw <a href="https://developer.android.com/guide/components/activities/tasks-and-back-stack" rel="nofollow noreferrer">Understand Tasks and Back Stack</a> but it doesn't answer my question. </p>