Entertainment
Air travel can be very tiring, especially if you have to wait in transit. Transit waits can last for hours and computers can be used to entertain people computers also allow people to remain connected to the rest of the world through means like e-mail and instant messaging.
Terminal Control
Busy airports can have 20 moving aircrafts at any one time. Information is constantly changing and is difficult track manually. This is why the modern airport control centre relies heavily on computers.