I know what are differences between Apache Kafka MM1 and Apache Kafka MM2.
Kafka MM1 doesn't support Active-Active setup and Offset syncing in also an issue in MM1 and many more
Overview of Active-Active Kafka Cluster using MirrorMaker 2.0
a-look-inside-kafka-mirrormaker-2
But i am not able to understand the differences between Replicator and Cluster linking.
Replicator was released before MM2 and offers most of the same features, but can also copy topic configurations, Schema Registry details, and partition changes (I don't think MM2 can do that, MM1 definitely does not).
AFAIK, cluster linking is almost like "serverless replication" ; it doesn't depend on running/maintaining a Connect cluster, as I believe it runs directly on the brokers, which also makes it not as scalable as a replication solution. It also requires restarting the brokers to enable/disable, as compared to simply starting/stopping a Connect cluster.