Airline Route List
Airline Route List (ARL)
shows all airports which an airline serves including its connection or code sharing partners. Although an airline may appear in the results for an airline, it may be served by a codeshare flight.
Code sharing or codeshare is an aviation business term for the practice of multiple airlines selling space on the same flights, where a seat can be purchased on one airline as if it was actually operated by a cooperating airline under a different flight number or code
Popular airline IATA codes are: Delta=DL, United=UA, American=AA, Southwest=WN