Bitcoin is a decentralized digital currency, without a central bank or single administrator, that can be sent from user to user on the peer-to-peer bitcoin network without the need for intermediaries. Transactions are verified by network nodes through cryptography and recorded in a public distributed ledger called a blockchain.

Bitcoin is unique in that there are a finite number of them: 21 million.

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.

The identity of the person who created Bitcoin is unknown. Satoshi Nakamoto is the name used by the unknown person or people who designed the original bitcoin protocol in 2009 and released it as open-source software in 2010.

The Bitcoin protocol requires users to enter a birthday upon signup, and we know that an individual named Satoshi Nakamoto registered and put down April 5 as a birth date. And that’s about it.

When Nakamoto ran the bitcoin software for the first time, he was rewarded with 50 bitcoins. This event is known as the “genesis block” and is still part of the bitcoin blockchain today.

Nakamoto is believed to own 1 million bitcoins, which would give him a fortune of more than $19 billion at today’s prices.

Bitcoin is decentralized, which means no government or bank controls it. That also means there’s no way to trace stolen bitcoins unless the thief decides to cash them out through an exchange that requires identification.

Once bitcoins are converted into cash, they can be traced through traditional financial channels like banks and PayPal.