What is BlockChain concept ? And from where to learn it ?

Answer 1

You tryed search it in google?

Answer 2

Blockchain is nothing but a ledger that keeps track of all the transactions of the users on the network. It is just a growing chain that is linked together with the help of cryptographic hash codes.

People are using blockchain technology for transparency because everyone on the network will know about your transaction, and security is enhanced since the data on the block cannot be altered by any means.

https://www.tutorialspoint.com/blockchain/index.htm