Warpspace was a "secret passage" through normal space that allowed for faster-than-light travel and time travel. Openings to warpspace resembled cracks, and ships travelling through would vibrate and could experience hyperspatial turbulence.
Humans travelled through warpspace. The colonists of the Elysium system, having survived a theoretically un-survivable situation, believed the Artifact affected warpspace and actually saved them. This led some of the colonists to believe the Artifact was God. (PROSE: Parasite)