# Lifetime ### Persistent vs. session-based entities When we connect to a Game World with a Game Client, the traditional approach is that all Entities originating on our Client are session-based. This means that when the Client disconnects, they will disappear from the network World for all players. A persistent object, however, will remain on the Replication Server even when the Client or Simulator that created or last simulated it, is gone. This allows us to create a living world where player actions leave lasting effects. In a virtual world, examples of persistent objects are: * A door anyone can open, close or lock * User-generated or user-configured objects left in the world to be found by others * Game progress objects (e.g. in PvE games) * Voice or video messages left by users * NPC's wandering around the world using an AI logic * Player characters on "auto pilot" that continue affecting the world when the player is offline * And many, many more A persistent object with no Simulator is called *an orphan.* Orphans can be configured to be auto-adopted by Clients or Simulators on a FCFS basis. --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://docs.coherence.io/1.0/coherence-sdk-for-unity/lifetime.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.