It's more or less a functional definition: if there are flights between Airport X and some other airport in a foreign country, Airport X is an "International Airport". There are some "International Airports" that have the name largely by historical inertia, such as Kansas City International Airport (MCI), which was constructed to be a major hub for Trans=World Airlines before TWA decided to move its hub to St. Louis instead (there ARE international flights from MCI to Mexico, but only seasonally).
Most (but not necessarily all) international airports will have some form of customs and Immigration services, but this is not actually required.
Not all airports are international airports, some are domestic airports.
No, not all are international.
Phoenix and Tucson are International Airports.
3 international airports...
The Airports Council International, commonly known as ACI, is a global trade representative of the world's airports.
There are 25 international airports in India. Some of these include Veer Savarkar International Airport, Calicut International Airport , and Chennai International Airport.
There are 3 international airports in Virginia. Washington Dulles International, Richmond International and Newport News International.
6 AIRPORTS
There is 6 airports in Tamil nadu ,3 international airports :Chennai International Airport , Tiruchirapalli International Airport, Coimbatore International Airport and 3 domestic airports :Madurai Airport, Salem Airport and Tuticorin Airport .
38 national airports and 8 international airports 10.05.2012
Alaskan Airports:Anchorage International AirportFairbanks International AirportJuneau International Airport
* International Airports in kerala: Trivandrum, Cochin, Calicut