Where is the file that lists all groups on a Linux system?

• A. cat /etc/groups
• B. grep 'GROUP' /etc/group
• C. /etc/group
• D. /etc/gshadow

Answer: (C)

The list of all groups on a Linux system is stored in the /etc/group file. This file is the canonical group database and includes each group’s name, the numeric group ID, a placeholder for the password, and the members of the group. On modern systems the password field is often not used, but the structure and purpose remain the same: it defines the available groups and who belongs to them. The other options don’t fit because /etc/groups is not the standard location for the group list, and grepping a file is just a way to search it rather than identifying where the list is stored. /etc/gshadow is a separate, secure file that holds password and membership information for groups, not the actual list of groups.