Usneallt82 is slightly off on the DFW
In 2000 or 2001, AA
opened its AAEagle satellite terminal. Prior to this, just about all AAEagle flights had a dedicated bus for each flight; you would board a bus at gates A1-A9, and the bus would take you straight to the plane. Some of the RJs would board at regular gates, usually gate A10 or A11.
After the satellite terminal was built, there is only one bus to take. From gate A2, the bus takes you straight to the satellite terminal, where you board your flight from gates A2A-A2K. The jetbridges at the satellite terminal are not real "jetbridges" per se; they are more like covered walkways that elevate to match the aircraft.
For a while, all of AAEagle's jet operations went through AA
's Terminal B gates. However, with the expansion of the jet operation, some ERJs have moved back to the satellite terminal. All CRJ operations still go through the B gates.