Warp drive is a method of propulsion that allows starships to attain warp lots speed, which is really really fast. Faster than light, actually. Invented by Zefram Cochrane in 2063, it was intended to expedite his travels to distant liquor stores and used-record shops. The Vulcans were suitably impressed by his altruistic goals, and decided to stop spying on the Earth after Cochrane's Phoenix broke the time barrier.
Or so he thought.
In fact, his warp drive has caused such shifting in the time-space continuum that accurate history has become impossible to record. Depending on where one is in the time stream, one may find that the first warp-capable Earth ship was
Other anomalies developed, such as a belief that Warp five was attained in the 2150's, but that the time barrier wasn't broken until the 2250's. For a time it was known that subspace radio wasn't invented until the early 23rd century, but history records that the Earth Starfleet routinely communicated in real time over much of the Alpha Quadrant.
Such contradictions rarely bother most people, but a race known as Canonites spends a great deal of time and effort trying to reconcile these conflicts. However one deals with these inconsistencies, all would agree that the source of the problem is warp drive.