this command modifies the group id por group name
groupmod mygroup
it is used to change the grpoup name
groupmod -n favourite mygroup
this command is used to change the group id
groupmod -g GID groupname
it is used to change already assigned GId to the the group
groupmod -o mygroup
it is used to chnage the password of the group
groupmod -p mygroup
it is used to change the groupname
groupmod -n mygroup
this command helps with the groupmod commands
groupmod -h