Bitcoin is a decentralized cryptocurrency that uses peer-to-peer technology and a blockchain to record transactions. It was created by Satoshi Nakamoto and the first block was mined on January 3, 2009. Bitcoin transactions are recorded on a blockchain, which is a distributed ledger that can be accessed by anyone to verify transactions. Transactions are verified by miners, who are rewarded with a set amount of Bitcoin and transaction fees. The supply of Bitcoin is limited to 21 million coins and it is divisible to eight decimal places. A wallet is needed to use Bitcoin and it consists of a public key, which is used to send and receive payments, and a private key, which is used to control the wallet. Bitcoin can be used for a variety of purposes, including everyday transactions, as a store of value, or for investment.