Yes, it is correct. At a distance both 2pc and paxos are solving the consensus problem - a group of entities agreeing on _something_. In the 2pc case, the _something_ is commit or not. In the paxos case, the _something_ is the chosen value. 2pc cannot handle coordinator failure, a single point of failure if you will. Transaction commit and replication are both consensus problems. You can use paxos for transaction commit as well. Lamport has a paper on a protocol called Paxos Commit.