Well it's pretty much the same as the in-app help, namely a HTML based help system for webbrowsers. So it consists of a bunch of directory structured files instead. This is good for using it as forum related references to specific topics etc. - For printing purposes a single contents PDF file would be of course more handy, but hey Affinity want's to sell it books too here. However you can fetch a copy of the online help for offline references via appropriate tools (like wget) for example: