In 2010 Barcelona El Prat airport has 2 terminals:

Terminal 1
Opened in 2009. Brand new.

Terminal 2
Terminals A, B and C are called Terminals 2A, 2B and 2C since terminal A opened in 2009.

Terminal 1 (T1) and Terminal 2 (T2) at Barcelona Airport are 4km apart and the only means of transfer between the two terminals is via a free shuttle bus service.

The brand new terminal 1, which opened in 2009, features 101 boarding gates and 43 air bridges, giving it an annual capacity of 30 million passengers.

In 2010 it seems that almost all airlines use terminal 1 at the airport. Only easyjet, german wings, air Berlin and maybe a few others (probaly all low cost)  seem to use terminal 2.