Command line expansion:

Command  Expansion: $ ( )

$ echo " This name is a $(nandhini)"

Because its displaying the output of one command as an argument to another.



Brace line expansion:

{}:

$ echo stu_mark{100,99,98}

Stu_mark100, Stu_mark99  Stu_mark98

rm -f  Stu_mark{100,99,98}

This command is used to removing files and directories with force

Create directory:

mkdir directory  name

Becasue this command give accessing permission to all .such as a read write and execution .


mkdir -p

-p is describing like as to displaying the multiple directories in the multiple time at the same level.