The proper name of warp drive. It operates (as far as I can tell) by pulling the vehicle partway into subspace to form a partial bubble unviverse. by distorting the bubble the reffrence point for the bubble is moved through four space untill the destination is reached where the bubble is reintegrated with four space.
This is extrapolated from the shows and books with lots of guessing. It is likely to be shown wrong by later episodes.
See also: Fractional Warp Velocities