What is considered a major airport?

A major domestic airport, within the United States, in most cases, is an airport that offers non-stop flights to New York.  However, the flight you’re confirmed on, may not be non-stop.  As for an international major airport, it would be an airport with non-stop flights to the United States.  However, as with flights within the United States, the flight you’re confirmed on may not be non-stop.