Wormhole

A wormhole is like a shortcut through space. Imagine a big road. It has lots of twists and turns and you have to go slow around all the curves, so it takes a very long time to get from one place to the other. A wormhole is like a tunnel through space, so if you wanted to get from one side of the big road to the other side, you could just go through the wormhole and you would get there much faster.