Why is "Blockchain" called a blockchain?
A very fundamental question before diving deep into more complex topics. What makes blockchain, a "Blockchain"?
Let’s break the keyword into 2 parts: Block and Chain
What is a Block?
A block is a representation of group of related records. It has 2 parts - a data field that represent these records and metadata (data about data) that describe the block.
Let’s assume you are recording few transactions in a ledger or notebook. Each page in the ledger can be considered a block and the transactions within it represent the block data.
Here’s a simple representation of a block, in the context of blockchain. (Credit - https://andersbrownworth.com/blockchain)
Block ID - Human readable unique identifier of a block
Nonce - A complex number that has to be rightly guessed by a miner, before a block can be successfully added to the blockchain
Data - Any functional data or group of records, usually encrypted
Hash - Machine readable representation of data in the block, that is unique to the data. Any change in data will result in a different hash
What is a Chain?
When the blocks are connected to each other, we end up with a chain of blocks. And thus we have a blockchain.
But how do you connect these blocks?
Pay special attention to the highlighted fields, “Hash” and “Prev”.
Value in the “Prev” field of Block #2 has the same value as “Hash” field of Block #1. So these blocks come after one another in a blockchain.
By extending this to thousands and millions of blocks, we end up in a massive entity common known as Blockchain.
So how do you explain Blockchain to your friend?
A blockchain is a massive distributed ledger containing blocks, which are nothing but a group of records, that are chained together using hashes. Any change to block data will modify the hash and thus break the chain
This distributed ledger is not stored in a single place, but spread across computers (referred as nodes) around the world.
In subsequent posts, I will cover certain important concepts around cryptography that makes the blockchain secure and immutable.
I strongly recommend you to play around with blockchains in this awesome demo website - https://andersbrownworth.com/blockchain/blockchain
Goodbye until next time and keep rocking!
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