A blockchain is a system of recording information in a way that makes it difficult to change, hack, or cheat the system. A blockchain is essentially a digital ledger of transactions that, unlike a bank’s ledger which is specific to that bank, is duplicated and distributed across the entire network of computer systems on the blockchain. Each cryptocurrency has its own blockchain, which is an ongoing, constantly re-verified record of every single transaction ever made using that cryptocurrency.  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. No single company, country, or third party is in control of a blockchain; and anyone can participate.