WinRAR how to change a backup file

Sometimes to process a large number of files, a long time does not know what files to back up, in fact, the use of WinRAR features can easily backup files, but also can be guaranteed to be the latest! Compress all the files under the backup folder into a Backup.rar file. Later in WinRAR, select the Backup folder, click the "Add" button on the toolbar, and note that the update mode is selected to "Add New update File", so that all the files under the backup folder are added to the Backup.rar file, as long as every day before work to do the same operation, Just open this file to ensure that your files are up to date.