DEV Community

Cover image for What does a Block look like in a Blockchain?

Posted on

What does a Block look like in a Blockchain?

Hey Guys,

Hope all are doing well.


Today we will see about the block, and what does it look like in a blockchain network.

I assume you are aware of block structure. If not, please read my previous article here.


Block is the head of a blockchain network. without blocks, you can't create a blockchain. and every block interlinked with each other. Let's see how.

Image description

As you can see in the above diagram, a block is consists of Nonce, SHA256, the previous block signature, and some transactions.

Genesis Block

The very first block is called a Genesis Block or Block 0. Because this block doesn't contain any previous block signature.

Able to understand somewhat?


Let's see other parts.


Every block must have a Nonce. A nonce is created by a miner, who mines the block into a blockchain network. These are generated in a particular way through the mining algorithm. It contains some value, and it is different from other nonce values.


SHA256 is a simple hash algorithm that crunches any length of data into a unique string of a fixed length. Each block has a different HSA256.

Eg. ba7816bf8f01cfea414140de5dae2223b00361a396177a9cb410ff61f20015ad


Genesis block doesn't contain a signature. Because, it is the very first block, or block 0. Once the genesis block is formed, the signature will be added to the next block. A signature is the HSA256 value of the previous block. Block 1's signature value is the same as Block 0's SHA256 value. Block 2's signature value is the same as Block 1's SHA256 value. And so on. With the help of this signature value, every block is linked with another block.


Each block contains some transactions, but not the genesis block. Transactions can be anything like let's say, A has 10 coins, B has 20 coins and C has 40 coins. A transferred 5 coins to B and C transferred 10 coins to B. Like this, every transaction is stored in a block.

I think you have got some idea about the block.


If you further need any help, try to connect with me. I’ll be happy to solve your doubts.

Till then, keep learning and keep smiling :)

Thanks for reading this. See you soon with a new article.

LinkedIn Twitter

Top comments (0)