1 - Steampunk is a genre of life (including hobby, writing and music) that merges an interest in the Victorian Time period and SF/F. Steampunk people seek to merge the technology of today (and the future) with the astetics of the past. This results in imagery that is best conveyed by the quote "Steampunk is what happens when Goths discover brown".

2. I first started hearing the term about 2 or 3-ish years ago, but I was late enough to the party that I'd say it probably is closer to 10 years old .

Edited to fix the worst of the "typing on a smartphone" errors