what is a jump drive used for
A jump drive is a speculative method of traveling faster than light (FTL) in science fiction. Related concepts are hyperdrive, warp drive and interstellar teleporter. The key characteristic of a jump drive (as the term is usually used) is that it allows a starship to be instantaneously teleported between two points. A jump drive is supposed to make a spaceship (or any matter) go from one point in space to another point, which may be several light years away, in a single instant.
Jump drives are also used in the Battletech series of games and literature. In the literature the drive is called the Kearny-Fuchida Drive, or K-F drive. Named for the physicists that developed the equations needed for the drive to work.