The visitor journey is every touchpoint from the moment a guest is invited to the moment they leave: invitation, confirmation, pre-arrival communication, arrival, check-in, the visit itself, departure, and follow-up.
Most visitor tools optimize one segment — typically check-in — and ignore the rest. Solo-practitioner VMS tools tend to invert this: the arrival is almost always the host themselves, so the leverage is in the pre-arrival and invitation stages.