chgrp stands for change group It is used to change one group's or file's ownership adds a group. In some distros it can be addgroup It changes the group of 1.txt file You can change the group to multiple files It changes the group for d2 directory and the files within it It changes the group for 1.txt file using the group of a
chown stands for change owner it is used to change the ownership of files and directories it changes the owner of 1.txt to root it changes the owner of a to root and gives a feedback It changes the owner of d3 directory and the files within it You can also change the owner and the group by using user:group it changes the owner and the group for log.txt
List the users on the system It displays information about specific user password passwd -l username → it locks the password for a specific user passwd -u username → it unlocks the password for a specific user passwd -d username → it deletes the user password passwd -e username → it expires the user password passwd -n 5 username → set the days of password expiration