In Unix-like operating systems, a group is a collection of users with similar permissions.

Groups can have multiple users as members, and users can belong to multiple groups simultaneously.

Like users, each group has a unique name and a unique identifier.

Creating a new group

To create a new group, you can use the groupadd command as follows:

$ sudo groupadd groupname

Where groupname is the name of the group you want to create.

Example

This command will create a new group named developers:

$ sudo groupadd developers

Listing existing groups

In Unix-like operating systems, every group on the system is listed in the /etc/group file, which is a text-database used for managing user accounts and group memberships.

To display this file, you can use the cat command as follows:

$ cat /etc/group

The /etc/group file format

Each line of the /etc/group file defines a group and consists of 4 fields separated by colon characters (:):