Bitcoin is a decentralized cryptocurrency that was first proposed by a person or group of persons using the identity Satoshi Nakamoto in a whitepaper published in 2008. It was introduced in January 2009.Bitcoin is a peer-to-peer digital currency, which means that all transactions take place between equal, independent network users without the need for a middleman to allow or facilitate them. A massive amount of computational power is used to verify all Bitcoin transactions, a process known as "mining."Although there have been some ideas for a similar form of decentralized digital currencies before Bitcoin, it is the first cryptocurrency to be used in the real world. Despite the fact that Bitcoin is not legal tender in most areas of the globe, it is extremely popular and has sparked the creation of thousands of rival cryptocurrencies known as altcoins.