What is blockchain

 Invention of the blockchain for bitcoin made it the first digital currency to solve the double-spending problem without the need of a trusted authority or central server

.Blockchain was invented by Satoshi Nakamoto in 2008 to serve as the public transaction ledger of the cryptocurrency bitcoin, 

Blockchain records are not unalterable ,blockchains may be considered secure by design

Blockchain is typically managed by a peer-to-peer network collectively adhering to a protocol for inter-node communication and validating new blocks .

Blockchain consist of timestamp and  transaction data , a crypotographic hash of the previos block .

Blockchain is aopen distrubuted ledger which has the ability to record transactions between two parties efficeintly , futher which  can be verifiable .

For business use private blockchain has been proposed. Snake oil is a term used by some marketting of blockchain . Cryptocurrencies is the blockchain which are  readable by the public.

A growing list of records is  called  as blocks. These blocks are linked using cryptography