What Is Steampunk?

So I have been wondering this for a while now. What exactly is steampunk? I know a little bit about it but I feel as thought the internet definitions can only give so much information. What do you guys think? Is steampunk a lifestyle? A fiction base? A for of a art? I think that steampunk has way more potential than people think. Share your ideas on what you think steampunk is and what you would like to see be done with it!