Also known as "wormhole gates," or mysteriously called "Einstein–Rosen bridges," jump gates were the pinnacle of human technology. Massive stations in each star system have huge, elaborate machines that somehow connect to, or possibly create, wormholes to other star systems. These passage ways cut directly through the fabric of space-time to allow starships to travel quickly around the galaxy.
Unfortunately, many of them were damaged in The Catastrophe. Only those with masterful engineering skills can even attempt to rebuild or repair them. Re-opening a jump gate is a major achievement and allows humanity access to new star systems.