Blockchain is a new way of sharing information that is extremely resistant to hacking. It may be the future of information exchange, but currently, it is mostly associated with bitcoin and cryptocurrency. Its similar to the way windows manages programs on your computer, but this manages blocks of data. It is a very complex, very secure, ledger, that keeps track of all transactions and will not allow alterations.
Bitcoin was created and Blockchain was pulled from its substructure. That is to say the chicken came before the egg in this case. The effective secure structure of the original Bitcoin programming was so remarkable that it eventually became its own program. With the addition of the “Smart Contract” it sealed the future of commercial transactions and Blockchain.
You read from the Harvard Business Review its “History of Blockchain”: https://hbr.org/2017/02/a-brief-history-of-blockchain