A Warp Drive, or in more specific terms, an Alcubierre drive, is a speculative mathematical model of a propulsion device that could theoretically travel Faster-than-light (commonly known as FTL). A Warp Drive is a method of stretching space in a way which would cause the fabric of space ahead of a spacecraft to contract and the space behind it to expand. The ship would ride this wave inside a region known as a warp bubble of flat space. Each level increases Warp Units travel Speed by 5%.
Warp Drive affects the speed of most units in the game, and is thus a quite useful technology that should be researched to high levels.