• Blockchain is a type of shared database that differs from a regular database in how it stores information; Blockchains store data in blocks, which are then linked to each other using cryptography.

  • As new data arrives, it is entered into a new block. Once a block is filled with data, it is appended to the previous block, causing the data to be chained together in chronological order.
  • Various types of information can be stored on a blockchain, but the most common use so far has been as a ledger of transactions.
  • In the case of Bitcoin, the blockchain is used in a decentralized manner, so that no one person or group has control - rather, all users collectively retain control.
  • Decentralized blockchains are immutable, which means that the data entered is irreversible. For Bitcoin, this means that transactions are permanently recorded and available for everyone to see.