A Blockchain is a process of linking the growing list of records using cryptography. Each record list, named as block contains a cryptographic hash of the previous block, a timestamp, and transaction data. The main aim of Blockchain is to provide resistance to data modification. The Blockchain maintains a record of all data exchanges, and it exploits a distributed system for transaction verification using a peer-to-peer network of nodes. After verifying the transaction, the new transaction is appended to the list, and so it cannot be altered. The Blockchain is a record-keeping technology behind the Bitcoin. Recently, the Bitcoin cryptocurrency has become a revolutionary technology for digital currency. The Blockchain is a core technology of digital currency for storage and transactions. It is a decentralized technology, and digital currency works efficiently without a central bank or administrator, and the transactions are shared on the peer-to-peer Bitcoin network without any intermediates. The network nodes verify the transactions through cryptography and stores the record in the Blockchain. Once a block is appended to the Blockchain, it is impossible to edit and delete the transaction.