In the first place, only the users who have lost data can deeply experience and realize the importance and necessity of backuping data on a regular basis. And the data backup software have been so inundant that we have almost no chance to verify and compare them one by one, so that we can pick out the best one. However, I suggest you put AOMEI Backupper at the top of the list of the data backup software you're going to test.

Iperius Backup is an automatic file, data backup freeware with flexible and powerful features, from Italy. It supports backup for multiple types of data (file/folder backup, drive imaging, database backup...), and various backup patterns (full backup, incremental backup... ) on all kinds of storage devices (USB hard drive, RDX drive, NAS, LTO/DAT tape drive, networked computer, cloud storage and FTP server).

FreeFileSync is an open source file/folder comparison and synchronization freeware with visual, clear and friendly UI, specially designed for assisting data backup on Windows, Linux and Mac platforms.