zulip/help/include/web-public-streams-intro.md

The public access option lets administrators configure selected streams to be web-public. Web-public streams can be viewed by anyone on the Internet without creating an account in your organization.

For example, you can link to a Zulip topic in a web-public stream from a GitHub issue, a social media post, or a forum thread, and anyone will be able to click the link and view the discussion in the Zulip web application without needing to create an account.

To see this feature in action, you can view web-public streams in the Zulip development community without logging in.

Users who wish to post content will need to create an account in order to do so.