What is Bitcoin? Maybe many of us still don't understand about Bitcoin. This article will briefly review this digital currency. Buying and selling transactions on the Internet lately have indeed been growing so rapidly. Not only in the transaction process that is increasingly diverse, now also has emerged a new virtual currency called BitCoin. Maybe there are some of you who don't know even the first time they hear the name. But since it was introduced in 2009, this unique currency has actually begun to be used by some e-commerce players in the world. More complete follows a review of whether and how the role of BitCoin as an online transaction tool.