Users provide the Air Planes in the air, the flight numbers, type of aircraft, etc...Flightawre might supplement that information from other sources, but users are providing the bulk of what you see on Flightaware maps...
Flightaware gives each user a very detail statistical page of the information they have provided, just as I type this response, my statistics page is saying I am currently providing information on 20 flights you see on the Flightaware Maps....I’m just one of literally thousands of individual users...
Go to MoneyWerx. He uses FlightAware to track flights worldwide. Amazing insight. Live tracks flights by current transponder data.
If you don’t know who he is, he has broadcasts on his PukeTube channel Monday, Wednesday, and Friday nights. You can play previous broadcasts also.
He tracks Guantanamo traffic and border traffic. Really good source of intel.