I recently came across this term and had no idea what it was. Maybe you've wondered too.
Read more at en.wikipedia.org
Steampunk is a sub-genre of science fiction, alternate history, and speculative fiction that came into prominence during the 1980s and early 1990s. Steampunk involves a setting where steam power is still widely used—usually the Victorian era Britain—that incorporates elements of either science fiction or fantasy. Works of steampunk often feature anachronistic technology or futuristic innovations as Victorians may have envisioned them; based on a Victorian perspective on fashion, culture, architectural style, art, etc. This technology may include such fictional machines as those found in the works of H. G. Wells and Jules Verne.