RouterOS backup feature allows you to save the current device's configuration, which then can be re-applied on the same or a different identical model. This is very useful since it allows you to effortlessly restore device's configurations or to re-apply the same configuration on a backup device. The system's backup file also contain the device's MAC addresses, which are also restored when the backup file is loaded. System's backups contain sensitive information about your device and its configuration, always consider encrypting the backup file and keeping the backup file in a safe place.