There are 2 kinds of chats in Zoom …
- In-meeting chat
- IM chat
The in-meeting chat is not recorded on any Zoom server. The in-meeting chat can be saved ...
- manually by any meeting participants.
- or automatically on local computer by host only if enabled - https://support.zoom.us/hc/en-us/articles/203650445-In-Meeting-Chat. Private messages between host and participant are saved. Private messages between other participants are not saved.
The IM chat is based on XMPP, the chats can be recorded in public Zoom cloud servers. We can configure the chat history storage in cloud in IM Management setting. The chat history storage can be disabled but the default is 24 months. There is also the option of enabling end-to-end encryption which will disable file transfer and screen capture features - https://support.zoom.us/hc/en-us/articles/207599823-End-To-End-Encrypted-Chat.