John F. Kennedy International (often referred to as Kennedy Airport, New York-JFK or simply, JFK) is the primary international airport serving New York City. It is the busiest international air passenger gateway into North America, the 16th busiest airport in the world, the 5th busiest airport in the United States, and the busiest airport in the New York airport system. JFK handled over 59 million passengers in 2017. Over ninety airlines operate out of the airport, with non-stop flights to destinations in all six inhabited continents. The airport features six passenger terminals and four runways.