In most cases, it is sufficient to install CopyRight2 either on the source or on the target. An exception to this is, if you want to perform an offline migration, where the source and target servers are not connected.
The realtime synchronization feature requires an installation on the source computer. It allows a continous replication of source data to the target, in order to eliminate the usual server downdown required for the final pass of a migration.
The same applies to the volume shadow copy feature, requiring an installation on the source system as well. It creates a snapshot of the source data when a copy job having it enabled starts and then accesses the data through the snapshot. This circumvents locked files, if users are still working, for example during the pre-copy phase of a migration using multiple passes. It will create a backup of the entire source file system, as it existed at the point in time when the snapshot was created.