related to replication of same data and getting multiple machines to agree on ONE value / order
used for:
- consensus on leader election
- ex: when 3-phase commit coordinator dies, participants must agree on new coordinator
https://chatgpt.com/c/6a8a3299-7614-83ea-a498-edf28caed4fd
- what is consensus vs consistency
- what is 3pc vs raft/paxos