If it has to do with other countries or their people, it is foreign, like a French movie receiving a British award for Best Foreign Film.
The adjective foreign is based on the Latin word foris, meaning “outside.” A foreign exchange student goes outside of his or her country to study. When you learn a foreign language, it is outside of the one you first learned. If you sleep late on the weekends, someone might say, "Getting up early on Saturdays is a foreign concept to you." This means it's outside of your experience and knowledge.