A digital system in which information is stored and exchanged in the form of blocks connected to each other in a way that makes it difficult or impossible to change.
Blockchain is the innovative technology that’s at the heart of almost all cryptocurrencies. It's a system of recording information, a sort of digital ledger of transactions, in a way that makes it difficult or impossible to change, hack, or cheat the system. How? By distributing identical copies (called "blocks") of a database across an entire network of computers systems (called "nodes"). Each block in the chain contains a number of transactions, and every time a new transaction occurs on the blockchain, a record of that transaction is added to every participant’s ledger with an immutable cryptographic signature. This means that if one block in one chain was changed, it would be immediately apparent it had been tampered with.