Universal naming allows actors to become universal actors. Universal actors have the ability to migrate, while anonymous actors do not. Service actors are special universal actors, with universal access privileges that do not get collected by the actor garbage collection mechanism.
Every universal actor has a Universal Actor Name (UAN), and a Universal Actor Locator (UAL). The UAN is a unique name that identifies the actor throughout its lifetime. The UAL represents the location where the actor is currently running. While the UAN never changes throughout the lifetime of a universal actor, its UAL changes as it migrates from one location to another. UANs and UALs follow the URI syntax. They are similar in format to a URL (see Table 4.1).