The term jet set refers to the international group of rich people who congregate at the world’s most fashionable resorts.
Members of the jet set are also members of the carriage
trade, due to their high net worth, but they may or may not
have the social status necessary to belong to the beau monde.
In short, to belong to the jet set, you need money, fashion
sense, and sufficient leisure time to travel frequently to
ultra-ritzy locales.
jet set = fashionable rich people who travel