Actor references and paths

When we create an Actor, what we get in response is an ActorRef. This is a reference to our created Actor. Why we might need an ActorRef is to pass throughout the system to other actors as a reference. These references are used for message passing. Every actor that we create has a reference to itself through self.

From within an actor, it's possible to obtain an actor reference of the calling Actor via a method named sender().

We can also give names to actor references. In our case, we named our SimpleActor reference simple-actor:

val simpleActor: ActorRef = system.actorOf(props, "simple-actor")

We also know that these Actors are created in a hierarchical fashion and we can give unique names to actor instances. Hence, these names together make a path for each Actor. The path is unique for each Actor. Our SimpleActor path might look like this:

We can see that due to the hierarchy, we have paths for different actors, because actors must have unique names. We can also...