In
Star Wars, the T/B is used by the
Imperials for bombing runs (
duh, what else?).
The T/B is slower then the standard TIE Fighter, but it has a stronger hull and can carry several missiles or other warheads. The T/B is usually escorted by T/Fs or TIE Interceptors.
Here is a little analogy:
X-Wing:Y-Wing::TIE Fighter:TIE Bomber