title: What is the use of other modes in AVAudioSession, when default mode is compatible for all categories?
body: <pre><code>// Access the shared, singleton audio session instance
  let session = AVAudioSession.sharedInstance()
  do {
      // Configure the audio session for movie playback
      try session.setCategory(AVAudioSessionCategoryPlayback,
                              mode: AVAudioSessionModeMoviePlayback,
                              options: [])
  } catch let error as NSError {
      print("Failed to set the audio session category and mode: \(error.localizedDescription)")
  }
  </code></pre>
  
  <p>Unable to understand the use of modes in audio sessions.</p>
  
  <p><a href="https://i.stack.imgur.com/Qiwp2.png" rel="nofollow noreferrer">modes here</a></p>