This page contains information regarding Star Trek: Prodigy, and thus may contain spoilers.
Proto-warp was a technology that allowed space travel at faster-than-light speeds. It was used as a propulsion enhancement system in the Protostar-type vessels launched by Starfleet in the late 24th century. It utilized a protostar located in the protostar engine. A third nacelle was needed in addition to the two warp nacelles when the drive was engaged. It was considered a high-priority system and used a large amount of energy. (PRO: "Terror Firma")