> For the complete documentation index, see [llms.txt](https://docs.coherence.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.coherence.io/manual/networking-state-changes/lifetime.md).

# Lifetime

### Session-based vs persistent

When a Client connects, the traditional approach is that all Entities originating on this Client are session-based. This means that when the Client disconnects, they will disappear from the network for all players.

When entities are configured as persistent, they will remain on the Replication Server instead, even when the Client or Simulator that created or last simulated it is gone.

Common examples of persistent objects could be:

* 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 that is not *adopted* by any Client is called *an orphan.* Orphans can be configured to be auto-adopted by Clients or Simulators on a FCFS basis.

<figure><img src="/files/ww4nawRIvRKoOse6Whbo" alt=""><figcaption></figcaption></figure>

{% hint style="info" %}
Persistence in this context refers to **session persistence only**. This means that players can leave the game, come back, and still find persistent objects and entities, as long as the World or Room is still alive.

However, as soon as a World or Room are being shut down, or the Replication Server is restarted, the state is lost.
{% endhint %}

{% hint style="warning" %}
Currently, the maximum number of persistent objects supported by the Replication Server is **32000**.
{% endhint %}