Blockchains are incredibly popular nowadays.
what is a blockchain?
as the name indicates, a blockchain is a chain of blocks that contain information.
this technique was originally described in 1991 by a group of researchers.
then it was originally intended to timestamp digital documents so that it’s not possible to back them or to tamper with them. almost like a notary.
however, it went by mostly unused until it was adapted by Satoshi Nakamoto in 2009 to create the digital cryptocurrency bitcoin.
a blockchain is distributed ledger that is completely open to anyone.
they have an interesting property
once some data has been recorded inside a blockchain, it becomes very difficult to change it.
find step by step knowledge about blockchain here:- http://blogparagon.com/what-is-blockchain/