Subscribers are database servers that receive replicated data. Depending on the type of replication, the Subscriber can propagate data changes back to the Publisher or republish the data to other Subscribers. In the Active Roles replication model, a Subscriber can propagate data changes to the Publisher and receive replicated data from the Publisher.
The Distributor is a server that hosts the distribution database and stores history data, transactions, and metadata. In the Active Roles replication model, the same server is used as both the Publisher and Distributor.
In the Active Roles replication model, the Publisher and its Subscribers are collectively referred to as replication group, with each server in the replication group being referred to as replication partner.
Replication group is comprised of replication partners that include a single Publisher and may include any number of Subscribers. When data in a replication partner’s database changes, replication ensures that the data changes are propagated to the databases maintained by all the other replication partners.
NOTE: In the SQL Server documentation, replication partners are referred to as synchronization partners.
When initially set up, the Administration Service’s database server is configured as a standalone server that does not belong to any replication group.