title: Difference between actor pools and groups in Akka
body: <p>I'm just starting Akka and I'm trying to understand the difference between actor pools and groups and when to use which. In the <a href="http://doc.akka.io/docs/akka/snapshot/scala/routing.html" rel="noreferrer">doc</a> it briefly says that a group is not created by a router, so that means they don't have a master?</p>
  
  <p>In the situation below, can you route messages directly from one worker group (or pool?) to another without sending it via the Master?</p>
  
  <p><img src="https://i.stack.imgur.com/ms0Hz.png" alt="Akka"></p>