Users and Groups:

• Users are assigned unique IDs (UIDs).

• Groups help manage permissions for multiple users.

Permissions:

• File permissions determine who can read, write, or execute files.

• Use the ls -l command to view permissions.

Principle of Least Privilege:

• Grant the minimum necessary permissions to users and processes.

Security Updates:

• Regularly update software to fix vulnerabilities.

• Commands:

  • Debian/Ubuntu: sudo apt update && sudo apt upgrade

  • Red Hat/CentOS: sudo yum update