# Permissions

Permissions: Permissions: Read, Write and Run, sudo and Who Owns a File.

Updated: November 10, 2026

1. [Permissions: Read, Write and Run](https://www.ask-codey.com/lessons/bash-permissions) (Apprentice): Every file says who may read it, change it and run it, for its owner, its group and everyone else; ls -l shows it as letters such as rwxr-xr-x, chmod +x lets a program run, and chmod 644 or 600 sets all nine at once with numbers.
2. [sudo and Who Owns a File](https://www.ask-codey.com/lessons/bash-sudo-and-ownership) (Journeyman): Every file has an owner and a group, and only root, the computer's administrator account, may change anything; sudo runs one command as root after asking for your password, and chown gives a file a new owner, so both are used rarely and on purpose.

Source: https://www.ask-codey.com/courses/bash-in-depth/topics/bash-permissions