dd command in linux used for disk dumping. using dd one can perform so many task in linux.

Understand disk dumping with an example

#dd if=/dev/sda of=a.txt bs=1M count=2000

in above command dd means disk dumping or dump data and it will create a file a.txt of size 2G

if = is input file which is here our hard drive /dev/sda

of = is output file which is a.txt here

bs = is base size which tells how much data dumped at once

count= is here the number of times data will be copied.