We now have a fairly good idea of how Linux provides resource security by separating administrator accounts from non-administrator accounts and then further applying specific user and group permissions for every folder, file, and resource on the system. By default, permissions are limited.

User and group accounts can be created, modified, or deleted by admins and permissions can be adjusted by typing just a few simple terminal commands.

Here’s what we learned:

• The different classifications of users and range of user ID’s
• What users and groups are in Linux
• How file-based permissions work in Linux:
  • owners and groups
  • read, write, and execute
• Commands used to create, delete, or modify users and groups:
  • useradd and groupadd
  • userdel and groupdel
  • usermod and groupmod
• Commands used to change owners and permissions:
  • chown
  • chmod
• Using sudo to access admin commands

These are just the fundamentals for navigating the users, groups, and permissions system on Linux! We encourage you to keep practicing to get used to the commands and the filesystem.