What is the meaning of "in residence" at a university?

This is the response I received from my graduate program's coordinator:

It just means physically being here, so doesn't have to be on-campus housing.

It means being on-campus for your studies: e.g., attending classes, doing research, collaborating on research, whatever. It's not a question about where you sleep at night (whether your home residence is in on-campus housing or not) so much as about whether you are physically here for your studies.

This is aimed at separating out "working remotely". If you are living on the other side of the country and trying to do your studies remotely, then you're not in residence at the university.