Bitcoin is a digital only currency that was created by Satoshi Nakamoto in 2009. The name, Bitcoin, is actually a reference to the software that Nakamoto used to create it, combined with the peer-to-peer network formed from the running of the software. Bitcoin is an online currency only, and is not regulated by the government, or any central bank. While it is not “real” money, it can be used as such at any site that accepts it. It can also be traded amongst users.
Currently, not many retailers accept Bitcoin. However, that may change as it is free to use, and there are no transaction fees attached to it’s use. When you combine these facts, along with how fast the popularity of Bitcoin is growing, it is not hard to envision a time when it will be widely accepted.