Fundamentally, transwarp drive is a generic term for technologies that overcome the limitations of conventional warp drive. The USS Excelsior NX-2000 was employed by Starfleet to test what was referred to as a transwarp drive in the 2280s. By the following decade, however, the ship was equipped with a standard warp drive. In 2450, the Star Triangle Advanced Guard obtained some Borg transwarp coils which were then duplicated and implemented on many STAG vessels. (Adventures of STAG)