What Is Blockchain?

What Is Blockchain?



2 min read

Hi, how is it going? ๐Ÿค™

Today we're going to explore the topic of blockchain. If you're interested in cryptocurrencies you've probably heard of the word Blockchain, but what is it? Let me explain it to you in a nutshell. ๐Ÿค“

Blockchain is a distributed database/state machine. This means that each network user holds a copy of this database locally - meaning the database is on more than one device. This database consists of records arranged in chronological order. This list consists of multiple data blocks, each block is linked to the previous and next block. The blocks document the time and order of transactions and they are linked in a way that makes it impossible to change the data or insert a new block between existing ones.

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Who participates in the Blockchain network?

Anyone can join public networks such as Bitcoin or Ethereum and become part of them. This network is based on peer-to-peer (P2P). It connects users, transfers transactions ( which will be discussed later in the article ), and blocks of verified transactions. The network is always based on the standardized Gossip protocol.

Blockchain security

All blocks are secured by cryptographic evidence (e.g.: signatures) and blockchain data synchronization security is ensured by consensus algorithms such as Proof of Work (e.g.: ethash). Many people believe that Blockchain is safer than banks because there is no central actor to control your money.

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But what is held in these blocks?

The blocks hold the transactions that make up the current state of the entire blockchain. What are transactions? They have verified changes in the state of the main state machine/database ( ie: the main ETH blockchain, for example). The transactions that are in the blockchain are verified by other users of the blockchain network.

Blockchain usually also has a reward system implemented based on providing its computing power for computations so-called: mining.


  • blockchain is a database distributed among the users of the network
  • it consists of blocks that are arranged chronologically and each block has one preceding and one following
  • any user may introduce a change to the blockchain, through transactions
  • for a chance to be introduced to the blockchain, it must be verified
  • by participating in the blockchain network we can share computing power, that is, to do so-called mining

And that in a nutshell is blockchain, in the next posts of the #IntroToCrypto series on the #codingbrah blog we will go much deeper into this topic.

Farewell ๐Ÿ‘‹

Bonus: A very good demo on how blockchain works can be found here โ†’ https://andersbrownworth.com/blockchain/blockchain

~ Kacper