Blockchain is a method of keeping the records of information in such a unique way that it is near impossible to change or modify any data in the blockchain. It is impossible to hack, cheat or modify its database.
We normally have an admin for the database who can edit, add or delete any data from the database but in blockchain, there is no admin who has control over the whole system/database.
A blockchain is a digital ledger of transactions that is duplicated and distributed across the entire network of computer systems on the blockchain. Each block in the chain contains a number of transactions, and every time a new transaction occurs on the blockchain, a record of that transaction is added to every participant’s ledger. The decentralised database managed by multiple participants is known as Distributed Ledger Technology (DLT).
Blockchain is a type of Distributed Ledger Technology (DLT) in which transactions are recorded with an immutable cryptographic signature called a hash. Distributed Ledger Technology (DLT) is secured, irreversible, anonymous and programmable.
Blockchain consists of blocks that contain data, that data can’t be reversed or modified. When data is stored in the blocks they generate a unique code or unique number for specific information and store this unique number/code in its next block. Every block contains 2 [hash] unique codes one of the previous block and 2nd of the current block. Block with no previous unique code/hash is called Genesis Block.
Distributed Ledger Technology (DLT) is secured, programmable, immutable, time-stamped, anonymous, distributed and unanimous. This means, blockchain is programmable such as smart contracts, smart contracts are used to make transactions through blockchain. Blockchain uses time-stamped, so it’s easy to keep track of transactions and track all of the data from its origins. Blockchain is secure, it is near to impossible to modify, update or change the current data in the blockchain and all the data is stored individually in encrypted form. Blockchain is anonymous and immutable, any validated records can’t be changed or irreversible.
This means if one block in one chain was changed, it would be immediately apparent it had been tampered with. If hackers wanted to corrupt a blockchain system, they would have to change every block in the chain, across all of the distributed versions of the chain.
Blockchains such as Bitcoin and Ethereum are constantly and continually growing as blocks are being added to the chain, which significantly adds to the security of the ledger.