Blockchain is a growing list of records, called blocks, which are linked using Cryptography. Cryptography is associated with the process of converting ordinary plain text into unintelligible text and vice-versa.
A blockchain is a time-stamped series of immutable record of data that is managed by a cluster of computers. Each block in the chain contains a cryptographic hash of the previous block a timestamp, and transaction data. Thus each of these blocks of data is secured and bound to each other using cryptographic principles.
The very primitive form of the blockchain was the hash tree, also known as a Merkle tree. It is a tree in which every leaf node is labelled with the hash of a data block, and every non-leaf node is labelled with the cryptographic hash of the labels of its child nodes. It is used for verifying and handling data between computer systems. It is a series of data records, each connected to the one before it. The newest record in this chain would contain the history of the entire chain.
A Blockchain keeps a record of all data exchanges. This record is known as a “ledger” in the cryptocurrency world. Each data exchange is a “transaction“. Every verified transaction is added to the ledger as a “block”. Once signed and verified, the new transaction is added to the blockchain and cannot be altered. Since it is a shared and immutable ledger, the information in it is open for anyone and everyone to see. Hence each block is transparent and everyone involved is accountable for their actions.
Blockchain utilizes a decentralized distributed system to verify each transaction. That means it has no central authority. This is the most distinct and important feature of blockchain technology.