Blockchain is a shared, peer to peer, immutable distributed ledger in which all the transactions are cryptographically secure. Blockchain provides users a decentralized public network which is not controlled by a single user or entity. It makes the system robust and secure against any sort of tempering with the data. Block chain helps peer to peer transactions without any intervention of the third party. Blockchain consists of more than one block and each block can be also referred to a node and each transaction is validated by each node. The very first block is known as Genesis block followed by n number of blocks. A single block consists of data and hash value (Unique Signature) which is depicted in the below diagram.