Superluminal interstellar travel (S.I.T.), often called faster-than-light travel or simply F.T.L. travel, is a method of travel that permits the user to vastly exceed the traditional speed of light, resulting in almost instantaneous transit between solar systems.
S.I.T. is the only way of transit that allows for a species to colonize habitable worlds within reasonable amounts of time.
The only way to achieve S.I.T. is to artificially build and sustain an Einstein-Rosen bridge, which is also known as an wormhole. A correctly sustained wormhole is able to link two solar systems, allowing space travel between the them.
Besides humanity, the only known species to have achieved S.I.T. is the protomolecule's parent race.