You've got a terminal open. There's a blinking cursor and probably some text like user@machine:~$. That's the prompt, and it's telling you more than you think. Let's break down what you're looking at.
The prompt
The prompt is the terminal's way of saying "I'm ready, give me a command." By default it looks something like:
user@machine:~$
That $ at the end means you're a regular user. If you ever see #, you're the root user (the super-admin). Be careful when you see # — root can do anything, including breaking things.
The ~ is shorthand for your home directory. More on that later.
Command structure
Every Unix command follows the same pattern:
$ command -options arguments
- command is the program you want to run —
ls,cat,echo, etc. - -options (or flags) modify how the command behaves. They usually start with a dash.
-lmeans "long format,"-rmeans "recursive." - arguments are what you're running the command on — a filename, a directory, some text.
Example: ls -l Documents runs the list command with the long-format flag on the Documents directory.
Man pages
Every command has a manual. Type man followed by the command name to read it:
$ man ls
This opens a scrollable document explaining every flag and use case. Press q to quit the man page and return to your prompt. Man pages can be intimidating at first — they're dense — but they're the definitive source of truth. When you forget what ls -la does, man ls has your back.
Getting help
Some commands also support --help for a quick summary:
$ ls --help
Use man for the full manual and --help for a cheat sheet. Between the two, you'll rarely get stuck.