Steampunk is a portmanteau of steam and punk. Steampunk art combines the DIY and anticonformist aspects of punk rock with aesthetics and technology from the steam age. Steampunk fiction often centers on an alternative-history version of Victorian-era England, where industrial steam technology is combined with science fiction elements such as space travel, mad scientists, and time travel.
Modern steampunk is primarily influenced by the works of Victorian science fiction writers such as Jules Verne and H.G. Wells. It also draws inspiration from novel technology of the time, such as Nikola Tesla's Tesla coils or Charles Babbage's mechanical computers.
The connection to ERE is that steampunk adherents have a DIY/anticonsumerist ethic of making their own possessions, so that they ideally meet their own needs and aesthetic tastes.