1 ) DD Command:-
The dd command stands for “data duplicator” and used for copying and converting data. It is very powerful low level utility of Linux which can do much more like.
• Backup and restore the entire hard disk or partition.
• Backup of MBR (Master Boot Record)
• It can copy and convert magnetic tape format, convert between ASCII and EBCDIC formats,swap bytes and can also convert lower case to upper case.
• It can also be used by Linux kernel make files to make boot images.
Only superuser can run this command because you can face a big data loss due to its improper usage, so you should be very careful while working with this utility. At that moment data loss can convert the dd utility as a “data destroyer” for you