This action starts the synchronization of differences. It uses the "Timestamp" field, which has to be created in the source table specified in General (FastTab)/Table ID. The function only synchronizes new or changed records from the last timestamp. If the "Timestamp" field doesn't exist in the database, synchronization works as does Actions (Ribbon)/Synch. All on SP. The synchronize type is specified in Synchronize (FastTab)/Synchronization Typeand this setting says which records are synchronized.