The chat’s archives stores each chat session, where you can view it at a later time.
The system archives a chat session once all chat members leave the room or after more than 20 minutes of inactivity. Chats appear in the Chat Sessions list.
Note For a general chat, you must be in the org unit where you created the general chat to see its session archives.
Links:
[1] http://staging.docs.d2l/en/taxonomy/term/3