This particular concept may differ couple to couple, but the spirit of the idea is to allow freedom while maintaining a structure that feels safe and secure at home.
More About Geographical Non-Monogamy
Geographical non-monogamy in practice could look like this:
Kristen and Corbin are monogamous at home, but when anyone travels out of the state, they agree that hooking up with someone else is okay. When they change times zones, they are allowed to have multiple partners. If the travel involves a passport, all bets are off!