title: iPhone background app - why does whatsapp work and skype doesn't
body: <p>I'm trying to wrap my head around how background apps work on iPhone. Specifically, Skype is not able to stay connected when the app is in the background, so you won't be able to receive calls/messages while in the background.</p>
  
  <p>On the other hand, Whatsapp is connected all the time and you are able to receive messages even when in background.</p>
  
  <p>Can someone explain the technicalities behind each app, the difference between them, and what prevents Skype from working like Whatsapp so its always connected?</p>
  
  <p>Thanks</p>