Image via WikipediaSteampunk is an art movement stemming from alternative history -- what if Charles Babbage's differential engine had worked, kicking off the Information age in Victorian times? The result combines Cyberpunk -- a grim cybernetic future where hacking cyborgs struggle against evil governments and corporations with superior skill, with Victorian fashion and steam-era technology, to form some sort of weird retro-future hybrid.
This does lead to some unusual technology choices. Steam was the power source of choice in Victorian times. If something needed energy, a boiler was the usual way to do it back then. Steam was well understood. Electricity was known, but it was known so poorly that it was seen as semi-divine, and only a truly mad scientist would be willing to mess around with it. So to make your car or train go? Steam. You need your computer to send signals? Steam based valve. You need to power your factory? Steam.
So...some very interesting art comes from this. Much of today's technology could have been made in victorian times, although they would have made it in a very different style. Brass instead of plastic. More showing of mechanism out of technological pride, than hiding it out of aesthetic purity. How would the world have been different?