The server that is designated as the bridgehead server is used for intersite replication.

Basic Replication : Basic replication is implemented using standard CREATE SNAPSHOT or CREATE MATERIALIZED VIEW statements. It can only replicate data and not procedures, indexes replication is always one-way, and snapshot copies are read only.

Advanced Replication : Advanced replication supports various configurations of updatable snapshot, multi-master and update anywhere replication. It is more difficult to configure but allows data and other database objects like indexes and procedures to be replicated.

Differences between Basic and Advanced replications:

- With basic replication, data replicas provide read-only access to the table data whereas advanced replication features extend the capabilities of basic read-only replication by allowing applications to update table replicas throughout a replicated database system.

- With Basic Replication applications can query data from local data replicas. On the other hand with advanced replication, data replicas anywhere in the system can provide both read and update access to a table's data.