1. Path vs Reference
Quote from official doc: An actor reference designates a single actor and the life-cycle of the reference matches that actor’s life-cycle; an actor path represents a name which may or may not be inhabited by an actor and the path itself does not have a life-cycle, it never becomes invalid. You can create an actor path without creating an actor, but you cannot create an actor reference without creating corresponding actor.
2. Logical Path vs Physical Path
logical path indicates the parental supervision relationship, regardless of where the parent/child is. With logical path you have a clear parental hierarchy view.
physical path indicates where the residing actor system is, especially for remote parent/child relationship. With physical path you have a clear actor physical distribution view.
3. Relative Path vs Absolute Path
4. Path vs Address
Each actor path has an address component, describing the protocol and location by which the corresponding actor is reachable, followed by the names of the actors in the hierarchy from the root up.
so, address seems equal to protocol + IP + port.
path = address + actor-hierarchy
5. actorOf vs actionSelection
References
[1] akka official documentation 2.4.1 (Java). http://doc.akka.io/docs/akka/current/general/addressing.html