Folder rule Action description
Synchronize Synchronize main folder with a selected (second)  folder: new or altered files from the main folder are copied into the second folder; then new or altered files from the second folder are copied into the main folder.

So, main folder has the advantage: if a file has been altered in any folder - main or "second" it will be copied from the main folder to the second.

If a file has been deleted it will be restored from other folder.

Copy/Backup to a folder Backup files from the main folder to a selected folder: new or altered files from the main folder are copied into other folder.
Copy/Backup to a FTP server Backup files from the main folder to a selected FTP server: new or altered files from the main folder are copied to a FTP server.
Monitor for changes The program monitors a selected folder in case of new or deleted files and sends  e-mail notifications.
Delete files by mask The program removes all files matching the input file mask from the folder.