Have you ever heard about Blockchain? It doesn't matter if you haven't heard of it. You must have heard about bitcoin. That will be enough for you to understand about Blockchain. Because the record-keeping technology of bitcoin is called a blockchain. Basically, blockchain is a kind of database. Now you will think that what is this database, a database is a collection of information that is stored electronically on the computer system, the information, and data in the database is set in a table format. Multiple users can use the database at the same time. The purpose of blockchain is to allow digital information to be recorded and distributed, but not edited. This technology was first introduced in 1991 by Stuart Haber and W. Scott Stometta, but blockchain found its first real-world application in 2009 with the launch of bitcoin.
Let us now know why it is called Blockchain? Blockchain collects information into groups and these groups are also called blocks. Each block has a limited storage capacity, so when a block is full, it gets added to the previously filled block. Such a chain is formed of data and hence it is called Blockchain. This blockchain is a chain of blocks that contain information, each block having a cryptographic hash of the previous block. This hash is generated on each transaction, this hash is a string of numbers and letters, the hash is a connection that converts the input of letters and numbers into an encrypted output of a fixed length. This hash does not only depend on the transaction but also on the transaction hash created before that in the chain, if even a small change is made in the transaction then a new hash is created. This means that if any attempt is made to tamper with the data of Blockchain, then its whole settings get changed. And in this manner, we can trace the tampering from the record. That's why it is a secure option.
This blockchain is spread over many computers and each computer has a copy of the blockchain. These computers are called 'nodes', by checking the hash of these nodes, it is known whether there has been any change in the transaction. If the transaction is approved by most of the nodes, then that transaction is written in the block. These nodes form the structure of the blockchain, they store, spread, and preserve the blockchain data. A full node is a computer-like device that has a copy of the transaction history of the blockchain. The blockchain updates itself every 10 minutes.