Some people think that blockchain "consensus" protocol is about collective decision making in the network - how miners create blocks? That the majority (51%) of nodes agree about the validity of each blockchain. No blockchain consensus has nothing to do with agreements in the network. Each node acts upon pre-designed rules and does not transmit its decisions. Moreso, each node is independent and cannot dump even a valid block receiving from anythor. Why? You would the node do it, you will learn in this video.
0:00 | Intro
0:32 | Nodes act independently
1:06 | How blockchain consensus works
3:11 | Rule of the longest chain
4:02 | 51% majority
5:04 | hardfork
See next:
Checkpoints on Blockchain https://youtu.be/mu6D2H3PhJs
The DAO crisis https://youtu.be/Qz9L5wxsaSw
