Paxos is a family of algorithms which are aimed at distributed consistency / monotonic state guarantees. However, Paxos allows for leaders with out-of-order logs to be elected leaders (provided they then reorder their logs) whereas Raft requires a server’s log to be up-to-date before it can be elected leader. Moreover, Raft has a reputation for having better understandability than Paxos.

edit: It looks like the linked paper covers the main differences, albeit in a more detailed manner. Also, it sems as if the author rejects the idea that Raft is more understandable and makes a case why he thinks Paxos is more understandable.