Bitcoin is a cryptocurrency and a payment system, first proposed by an anonymous person or group of people under the name Satoshi Nakamoto in 2008.
Bitcoins are created as a reward for a process known as mining. They can be exchanged for other currencies, products, and services.
As of February 2015, over 100,000 merchants and vendors accepted bitcoin as payment.
Bitcoin is pseudonymous, meaning that funds are not tied to real-world entities but rather bitcoin addresses. Owners of bitcoin addresses are not explicitly identified, but all transactions on the blockchain are public.
In addition, transactions can be linked to individuals and companies through “idioms of use” (e.g., transactions that spend coins from multiple inputs indicate that the inputs may have a common owner) and corroborating public transaction data with known information on owners of certain addresses.
The cheapest Bitcoin price was in 2009 when it was first created and worth nothing. However, by December 2017, Bitcoin reached an all-time high price of $19,783 per coin.