Last Successful: The last time a sync was successfully completed, whether it be an automated/scheduled sync, or a manual.
Next Scheduled: If you have set an sync interval, this will display the next time an automated sync is scheduled.
Verbose Output: When checked, details of the items being synced will show in the main output pane above.
Mute Clicks: On some systems, when the output pane is updated during sync, Windows produces the sound of a mouse clicking. To prevent this, check the box.
Start Sync: Perform a manual, on-demand sync. The default will be a differential sync - only changes since the last sync.