Data backup devices include CD-RWs, DVD-RWs, DATs, etc., any device that Windows recognizes as a drive, and you can also backup on a network drive.
The unit of the data is 1 minute, and can only be viewed through DVR software itself or you can create an .avi file for play back on standard media players. Data backup is also possible on the Search program, where it can be saved in AVI format, making it conveniently viewable through the Windows Media Player (by enabling "View-Caption" from the menu, you can also conform information data).