> For the complete documentation index, see [llms.txt](https://btcjourney.gitbook.io/start/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://btcjourney.gitbook.io/start/how-does-bitcoin-work/what-is-happening/reaching-decentralized-consensus.md).

# Reaching decentralized consensus

This video by 3Blue1Brown covers the issue that arises when you have a large network of nodes trying to come to an agreement on what to do, and explains the *proof-of-work* consensus mechanism in more detail.

| Creator     | Time | URL                                                        |
| ----------- | ---- | ---------------------------------------------------------- |
| 3Blue1Brown | 8min | [Full source](https://www.youtube.com/watch?v=bBC-nXj3Ng4) |

{% embed url="<https://www.youtube.com/embed/bBC-nXj3Ng4?end=1183&start=668>" %}

{% hint style="info" %}
**Takeaway** A rule is needed to ensure a distributed network with no authority can agree on what to do. The proof-of-work consensus mechanisms uses cryptography and code to help nodes agree what new transactions to add and allows us to verify the entire history of transactions that have gone before. This enables full agreement and consensus without any central authority, which is groundbreaking to have been implemented at scale.
{% endhint %}


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