Bitcoin is a decentralized peer-to-peer network and the leading digital currency in terms of overall market size. Bitcoin was first proposed via a 2008 white paper authored by a pseudonymous programmer or a group of programmers, known as Satoshi Nakamoto. The network went live on Jan. 3, 2009. The Bitcoin network itself comprises thousands of distributed nodes that independently verify transactions made using BTC. Unlike all previous payment networks, Bitcoin functions without reliance on a central authority. Bitcoin miners group BTC transaction data and record it in blocks. Each block is cryptographically linked to the previous block, creating a chain — known as a blockchain. This linkage ensures previously recorded data is incredibly resistant to change. In the years since its launch, Bitcoin has attracted increasing mainstream interest. Today, there are an estimated 100 million Bitcoin users, and tens of thousands of merchants accept BTC payments worldwide. The growth of Bitcoin adoption as a means of payment, a money transfer system or a savings vehicle has seen the BTC price and market capitalization increase significantly. In February 2021, the total value of all BTC in circulation passed $1 trillion for the first time.