an openly distributed ledger system that records all crypto currency transactions worldwide and everyone can view transactions recorded in a block-chain system that make it easier for further audits. The block chains system of all transactions is recorded in a clear and systematic way so that no one can manipulate the block chain system because it is a technology-generated system or can be called decentralized that has no authority BlockChain's technology is a remarkable method of the current digital era. BlockChain technology is used in many countries around the world. I do not know much about blockchain. I think the blockchain system is a complicated system, so I want to know more about it.