How does visible Light travel through outer space?

By the electromagnetic "vibrations" that make up light. Said EM vibrations are an electric field and a magnetic field at right angles to each other and to the direction of propagation/travel. Light travels by the same "mechanism" that X rays travel, radio waves travel and anything else in the vast electromagnetic spectrum. Probably how I'm able to type these words on a computer key board and have them transmitted "Wi Fi" like, to you, the hapless recipient. You're a Cheetah? That means you can run like the wind?