Bitcoin is a peer-to-peer digital payment system in which transactions are verified by nodes on the blockchain, which is a public distributed ledger. The nodes (usually a group of “miners”) form a worldwide network by running the open-source Bitcoin software on their systems and “mining” blocks. A block is a collection of transactions making up 12.5 bitcoin which, when linked together with other blocks, forms the blockchain. It exists without any real centralization or intermediary. Over 100,000 vendors are now accepting bitcoin as a payment medium. With over 5 million people using bitcoin, it is the leading cryptocurrency by quite a margin. A bitcoin (uncapitalized) is the unit of account of the Bitcoin system which is paid out to miners upon successfully mining a block.
Bitcoin uses peer-to-peer technology to operate with no central authority or banks; managing transactions and the issuing of bitcoins is carried out collectively by the network.