the National Institute of Standards and Technology (NIST) has launched an easy introduction to blockchain, which underpins Bitcoin and different digital currencies. (59 pages) A blockchain is basically a decentralized ledger that maintains transaction data on many computer systems concurrently. Once a bunch, or block, of data is entered into the ledger, the block’s data is related mathematically to different blocks, forming a sequence of data. Because of this mathematical relationship, the data in a specific block can’t be altered with out altering all subsequent blocks within the chain and making a discrepancy that different record-keepers within the community would instantly discover.

This article sources data from NextBigFuture.com