Guides

Longer reads that build the mental models behind the commands — each with an embedded terminal to practice in.

The command reference answers "what does this do?"; these guides answer "why does it work that way?". That difference matters more than it sounds: once you understand that a filename is not the file, that the shell expands wildcards before any command sees them, and that every process reads and writes three streams, dozens of behaviors stop being arbitrary rules to memorize and become predictions you can make yourself.

Read them in any order. If you are starting from zero, the beginners guide first; if you keep hitting "Permission denied", go straight to permissions; if your commands work but you cannot combine them, pipes and redirection is the one that unlocks everything else.