By Kapil Gauhar


Cardano Blockchain

Blockchain Programming

Classification of Blockchain

Blockchain this, Blockchain that… the list goes on and on and on and… on!

Much has been talked about Blockchain Technology, Isn’t it?

Nobody is trying to dig deep into it! That’s what we are going to do today!

Together! What do you say?


Let’s Unravel The Blocks Of Blockchain…

What’s Blockchain? (Just an OMEN)

The blockchain is a distributed ledger used for recording transactions.

That’s it! No more complex definitions!

Let’s dive little deeper into the technology.

Blocks – What Is This Term?

Blockchain Blocks

The transaction data is permanently recorded as files. That file is referred to as a BLOCK. Over the time, blocks are assembled into a linear sequence. Miners are constantly processing new transactions into the new blocks which are then added to the end of the chain. Since blocks are buried deeper into the blockchain, they become even harder to change. This is what gives rise to the Irreversible Transactions.

Every single block contains a record of all the recent transactions, as well as reference to the previous block. It contains an answer to a mathematical puzzle which is difficult-to-solve. The answer to the puzzle is unique to each block. Though the mathematical puzzle in each block is complicated to solve, yet it is straightforward for the rest of the network to verify the solution as correct, once a valid solution is found.

You May Also Read: 5 Best Bitcoin Mining Hardwares

Structure of a Block

Structure of a block

As stated above, a block is a container of the data structure. A block, in the Bitcoin world, contains over 500 transactions on average. The average size of a block appears to be 1MB. If talking about Bitcoin Cash, then the size of a block can go up to 8MB. The size of a block decides the number of transactions to be processed per second.

Anyway, a block is composed of a long list of transactions and a header. Shall we begin with the header?

Block Header

Block Header

The header in a block contains its metadata. There are generally three different sets of metadata –

  1. The previous hash. Make sure that every block, in a blockchain, inherits from the previous block since the address of the previous block’s hash is used to create the new block.
  2. Mining competition. A block needs to be given a valid hash to be a part of the blockchain. This contains the difficulty, the nonce, and the timestamp. Mining is another vital part of the Blockchain Technology.
  3. A Merkle Tree root. It is about the data structure to compile the transaction in the block.

Block Identifier

Block Identifier

For identifying a block, one has a cryptographic hash and a digital signature. Now, this is something that is created by hashing the block header twice with the SHA256 algorithm.

For instance,

The block header hash for a particular block is –


We can also see the previous block’s hash –


Remember that we used the second hash for creating the first. Every block utilizes the previous block’s hash to construct its hash. The block hash is a different identifier. You will not find two blocks with the same hash.

Another way for identifying a particular block is the block height. That is the position of a block in the Blockchain. Let suppose if a block’s position is 500312. This indicates that there are 500311 blocks before that one. 500312 blocks have been created by far since the creation of bitcoin blockchain.

However, a block’s height isn’t unique. Many blocks can compete for the same position in the case of a fork, such as Bitcoin Cash.

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Kapil Gauhar

Kapil Gauhar is the founder of Blogger’s Gyan. He is a Passionate Blogger, a Big Thinker and a Creative Writer. His passion for doing friendship with words and letting people know about the wonders of the Digital World is what motivates him to take writing as a career.

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