FTL stands for Faster Than Light.
FTL is the way ships travel large distances through space. If the distance is long enough stasis pods can be used to sleep through the rest of the journey.
The capabilities of FTL have been surpassed with the invention of the Blink Drive.
During certain circumstances, FTL can be made inaccessible within certain zones of secured space through a technologically caused phenomenon known as the Aslanoff Exclusion Field. These patches of satellite packed space give off a field that can disrupt an FTL window, which forces the ship to drop out. Fortunately, sublight can still be assessable through these regions.