CardDAV, CalDAV. Hows does it work?

Where can I find informations how to use CardDAV and CalDAV? The help file page is empty, and I have no idea. It seems to be impossible. I can create an account  let’s say for CalDAV. But this is then an account for Calendar and Contancts, whjat cant work because there are two different addresses for addressbooks and calendars.

It seems, this is not a Feature…?

I am not sure what your issue is or what you wish to accomplish with this set up?
The option is that your CardDAV and CalDAV will be set up together with your email account, but if you have these separate from your mail, you can set them up separately and then link them to a mail account manually.
Please describe your problem in more detail.