Bitcoin (BTC) is a decentralized cryptocurrency that was first described in a 2008 whitepaper by an individual or group of individuals using the alias Satoshi Nakamoto. Officially launched in January 2009, Bitcoin is a peer-to-peer online currency that allows transactions to happen directly between equal and independent network participants without the need for any intermediary. Bitcoin is recognized as one of the initial cryptocurrencies to come into use and has inspired the development of thousands of competing projects. There will only ever be 21 million BTC. Bitcoin is highly divisible, with its smallest unit, i.e. 0.000 000 01 BTC, called a "satoshi" or "sat." As bitcoin's value has risen, its easy divisibility has become a key attribute.