There are 2 airports in Rome – please see details on both below.

1. Fiumicino Airport
Departure:
Terminal 1 (Ex Terminal A) -  flights of Alitalia (also flight of other airlines - code share with Alitalia + all the domestic flights)
Terminal 2 (ex Terminal AA) - some charter & low cost airlines
Terminal 3 (ex terminal B + C) - all the rest of the flights, except the flight of the U.S.A. airlines
Terminal 5 - all the U.S.A. airlines
 
Arrival:
Terminal 1 (ex Terminal A) - all the domestic arrivals + all the ALITALIA arrivals (incl. code share)
Terminal 3 (ex Terminal B) - all the other arrivals

To reach the airport of Fiumicino, you can use the Leonardo Express, direct train from Termini Station – cost of the ticket (at the moment) – Euro 11,00 and this will take around 30 min. There is one train every 30 min. You can also use the line FM1 (Fara Sabina – Fiumicino). There is a train every 15 min. The cost of the ticket is Euro 5,50.

Please see further information on all train lines at www.ferroviedellostato.it

2. Ciampino Airport:
Ciampino airport is small and has only 1 terminal with arrival & departure. Most of the low cost airlines fly into this airport. You can travel to the city centre from this airport via:
http://www.sitbusshuttle.it/
http://www.terravision.eu/