Blockchain Technology is an emerging technology in the software world. In order to understand the applications of the blockchain, it is necessary to understand how blockchain works. Blockchain was first introduced by Satoshi Nakamoto in 2008, which serve a Peer-to-Peer ledger for registering cryptocurrency bitcoin transactions. The blockchain is a list of records stored in the form of a chain. A blockchain is a decentralized distributed ledger which means a number of records are stored in a block and the block is added to the chain. Each block consists of a number of transactions for each transaction there will be a unique hash value, all hash values of the number of the transaction are combined and made a single hash value of the block and this follows Merkle root hash method. The invention of blockchain in cryptocurrency bitcoin solved the issue of double spending. The invention of blockchain in data backup can decrease the security complexity and duplication of the data. Rather than storing the data in one single hub that is the centralized system we can store the data in the blockchain which is a decentralized distributed ledger. In this decentralized system, the file is divided into a number of chunks stored into the blockchain which makes it difficult for data hacking and data tampering. In a centralized system if a server goes down then data is lost forever and in centralized system records can easily be altered because it does not have a backup to verify the records but in the blockchain, every peer in the network has the copy of the records and it is difficult to tamper the records. The files can be divided by a technology called Reed-Soloman erasure coding, generally used in CDs and DVDs. Reed-Soloman erasure coding allows dividing files in a redundant manner, where any 1 of 3 segments can fully recover a user's file.