DSE Advanced Replication terminology 

Terminology that is specific to DSE Advanced Replication that supports distributed data replication from remote DataStax Enterprise edge clusters back to a hub cluster.

This terminology is specific to DSE Advanced Replication that supports distributed data replication from remote DataStax Enterprise edge clusters back to a hub cluster.
collection agent
The process thread that runs on the source cluster that captures the incoming changes and populates the replication log.
destination cluster
When the data flow is going from the edge cluster to the hub cluster, the hub cluster is the destination cluster.
edge cluster
A cluster at the remote site that primarily sends data to one or more hub clusters. The edge cluster is sometimes referred to as the spoke in hub-and-spoke architecture. DataStax Enterprise 5.0 or later is required and DSE Advanced Replication must be enabled on the edge cluster.
edge datacenter
A datacenter of an edge cluster.
hub cluster
A cluster that is central to the topology and supports one or more edge clusters that replicate data to the hub cluster. DSE Advanced Replication is not required on the hub cluster.
hub datacenter
A datacenter of a hub cluster.
isolated
The state of a cluster when there is not a live connection between the edge cluster and the hub cluster.
replication agent
The process thread that runs on the source cluster that reads data from the replication log and transmits that data to the destination cluster.
replication channel
A defined channel of change data between edge clusters and hub clusters. A replication channel is defined by the edge cluster, source keyspace, source table name, hub cluster, destination keyspace, and destination table name.
replication channel priority
The priority order of which replication channel has precedence when limited bandwidth occurs between the source cluster and the destination cluster.
replication log
The replication log on the source cluster stores data in preparation for transmission to the destination cluster.
source cluster
When the data flow is going from the edge cluster to the hub cluster, the edge cluster is the source cluster.
tethered
The state when there is a live connection between the edge cluster and the hub cluster.