A Page is a living document in ChatGPT. It lives in Space in the sidebar, not inside a single chat, so it outlasts the conversation it came from. You can share it with viewers or editors, and people can edit at the same time.
Pages are on Pro, Business, and Enterprise. One thing to remember when sharing: what ChatGPT wrote using your personal context can be visible to the people you share with, so read a Page before you share it. On mobile, Pages are read-only.