If considering the topic Blockchain, the first example that comes to your mind will be Bitcoin. Looking at the facts, the record-keeping technology behind the digital token Bitcoin is Blockchain and this is a ledger that stores information on who owns the Bitcoin. Now, what is a blockchain? As the name suggests blockchain also called Distributed Ledger Technology (DLT) is a chain of blocks that contains information. Blockchain technology is intended for timestamping digital documents and for transferring money, property, contracts, etc… securely without the interference of third-party. Once the information is recorded, it will be impossible to backdate or tamper the information stored. Some important advantages of blockchain technology are listed below.

• The blockchain technology doesn’t require a third-party intermediary for verification
• Eliminate the double-record problem without a centralized server.
• Data can’t be altered instead it is appended as a new block.
• Cryptography hash function secures the data from cyber-attacks.
• The stored data will be transparent to authorized public and data will be immutable.
• Eliminates duplicate entry and fraudulent activities

Blockchain Architecture

A blockchain is a replicated architecture that can be implemented in different sectors like IoT, healthcare, finance & accounting, government organizations, and more because of its high-level security.  As mentioned earlier, it is a chain of blocks where each block contains verified data(that depends on the blockchain). If we are considering a block of bitcoin, the data that will be stored are sender, receiver, and transferred bitcoin count. 

For a blockchain, the initial block is known as the Genius block and new blocks are appended to the previous block in the network. To improve the security of the data, the blockchain technology makes use of SHA cryptographic hash function. Other than the data, all the blocks will also contain a hash and hash of the previous block(except for Genius block). In case of any fraudulent activity on blockchain alter any block data, the corresponding hash of that block will also be updated. Since this hash value is stored in the next block, it makes the succeeding block invalid.