An expatriate (expat) is an individual who is living outside of their passport country, but with no intention to settle permanently or pursue citizenship in their host country.

A Third Culture Kid (TCK) spends a significant part of their developmental years living in a country that is different from at least one of their parent’s passport country(ies). An Adult Third Culture Kid (ATCK) (or Third Culture Individual) is someone who was raised, abroad for a significant part of their childhood. Put simply, an ATCK is a TCK who is now an adult.