For UNIX and Windows servers, enabling capture for a table sets up triggers to continuously capture changes on the table; and disabling capture removes those triggers. For IBM i servers, enabling change capture informs the DB2 Change Selector about which records it must capture from the transaction logs of the DB2 sending tables.
Change capture options are available on Replication and Synchronization requests. Enable Capture is different from Start Request. It forcefully enables table capture of all the source hosts of a request. The data that needs to be moved is collected and sits ready to be sent as soon as the Change Selector starts. A Start enables table capture as well, but in addition, it allows the flow of data from source to target hosts since it starts the Change Selector.
You can also disable capture, which allows you to exclude certain requests/tables from change capture.
Once enabling capture completes, Connect CDC components capture any updates made to the data in your sending table. Replicas of those updates are sent to your target table when the replication request starts.