Raft
In plain terms
A consensus algorithm designed to be understandable.
Going deeper
Raft elects a leader that replicates a log of operations to followers, keeping the cluster consistent and handling failures with re-elections. It's popular because it's simpler to reason about than alternatives like Paxos.
Under the hood
Uses randomized election timeouts to avoid split votes and an append-only replicated log; chosen over Paxos in practice for understandability.
Examples
etcd, Consul, CockroachDB, TiKV, distributed key-value stores.
Think of it like...
Like a team electing one captain to call the plays and make sure everyone writes the same playbook, holding a new vote if the captain disappears.