Guest, or a temporary account
Most guest modes create a record with an identifier and no address attached. That is different from having no record at all, and the difference shows in what survives a closed tab, what the server logs, and whether the conversation can be recovered later.
The word guest suggests nothing is kept. Sometimes that is true, and more often it means the account has no name on it, which is a weaker claim than it sounds.
On this page
A guest usually has an identifier
To keep a conversation going across messages, something must tie them together. That something is an identifier stored in your browser and echoed to the server. It is an account without a name, and calling it guest describes the missing name rather than the missing record.
What survives the tab closing
If your conversation is still there after closing and reopening, the record outlived the session. If it is gone, the tie was in the tab. This is the fastest test, it takes 30 seconds, and it distinguishes the 2 arrangements better than any wording on the page.
The server log is separate again
Even where nothing about the conversation is kept, a request log with an address and a timestamp usually exists, because it is how any web service is operated. Guest mode makes no promise about that layer, and a page describing guest mode is not describing it.
Where the distinction matters
It matters when you expect a conversation to be unrecoverable. A guest record with an identifier can usually be found again by whoever holds the database. A conversation with no record cannot, and only the second matches what most people assume guest means.
Questions before you start
Does clearing cookies delete a guest account?
It removes your key to it. The record on the server is unaffected, and whether it is deleted depends on retention rather than on your browser.
Is guest mode the same as a private window?
No. A private window controls what your own device keeps. Guest mode controls what the service attaches a name to, and the 2 are unrelated.
Can a guest conversation be linked to me later?
If you sign in afterwards, many services attach the guest record to the new account. That is a feature, and it is worth knowing before treating guest mode as separation.
Open a chat where there is no account to be a guest of.
Open chat without login