# What's blockchain?

**Published by:** [Web3withAshley](https://paragraph.com/@web3withashley/)
**Published on:** 2022-04-02
**URL:** https://paragraph.com/@web3withashley/what-s-blockchain

## Content

Blockchain is the heart of web 3 — it’s the tech underlying NFTs, cryptocurrencies, and DAOs. But what actually is it? Put simply, blockchain is a new method of recording information. Rather than relying on a single server (computer), blockchain operates over a network of servers allowing us to create a decentralized, transparent, and public record of information that cannot be altered or deleted. How does it work? Whenever you want to record information on the blockchain, your request is stored into a block with a bunch of other requests. Once a block is full of information, it gets sent to a group of miners. Miners must verify if your requests are real or if they are fake. The process of doing this can be very energy intensive because many blockchains (BTC, ETH) require a lot of computing power to decrypt the answer. If all the information in the block is valid, the block will be verified and added to the chain of pre-existing blocks in chronological order. Once the information is added to the chain, the information is automatically replicated across all the other servers in the network. This effectively creates a public ledger of information which anyone has access to. In addition to being public and distributed, the blockchain is also immutable, meaning you cannot change or erase what has happened in the past. This is because of the majority rules consensus mechanism: a change to the blockchain will only occur if the majority of servers in the network verify that the change is legit. So if one person tries to change the truth, and hack a computer to say the transaction was for $100 instead of $10, they won’t be able to because the rest of the computers in the network will say otherwise. Majority rules. What happens on the blockchain, stays on the blockchain. Example: Ashley goes on a wallet website and clicks a button to send Matt $10 Ashley’s computer server puts that information into a block One the block is full of other people’s requests, it will be sent to the miners The miners will solve cryptographic equations to verify the information If the entire block is verified, it will be added to the blockchain One a block is added it gets replicated to all the servers in the network All of the servers now operate under the assumption that Ashley sent Matt $10, their wallets will reflect this change Now let’s say that person Matt wanted to hack the record and say that the transaction amount was $100 instead of $10 If Matt only hacks one computer, that computer’s record would be rejected by the rest of the servers in the network. In order to change the requests within the block from $10 to $100, Matt must be in control of >50% of the servers in the network Thanks for reading! Please reach out to @web3withashley on twitter if you have any questions or suggestions of how this article can be improved!

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