by using this command we can get groups under that username

no username is passed then this command will display group membership for the current user

it id of linux group

it gives all the group names 

by using this we can get the list of all groups 

print the first field containg the group name

cuts the first filed and displays only the group name

Example Output:

devops sudo docker
Explanation:
Displays all groups the current user belongs to.

Output Example:

alice : alice developers sudo
 

Explanation:
Shows all groups that alice belongs to.

Output Example:

root : root admin sudo
 

Explanation:
Displays all groups assigned to the root user.

Explanation:
Displays all system groups and their members.

Example:

groups alice | grep -w sudo

Explanation:
Checks if alice belongs to the sudo group.

Output Example:

sudo:x:27:alice,bob,admin

Explanation:
Shows all users in the sudo group

Explanation:
Adds user alice to the docker group.

Explanation:
Removes user alice from the developers group.

Example:

id -gn bob

Output Example:

bob

Explanation:
Shows the primary group of user bob.

Example:

id -G -n alice

Output Example:

alice developers sudo

Explanation:
Displays group names instead of numeric IDs.

Displays the groups a user belongs to.