Which command is used to add an empty group to the system?

The groupadd command is used to add an empty group to the system. It takes the name of the group as an argument and creates an entry for it in the /etc/group file. The groupadd command also assigns a unique group ID (GID) to the new group. The groupadd command can take various options to specify the GID, the password, and other attributes of the new group. For example, groupadd -g 1000 mygroup will create a new group named mygroup with a GID of 1000. References:

Linux Groups - javatpoint

groupadd(8) - Linux manual page

How to Add and Delete User Groups on Linux