What is a terminal, really?

In Level 0 you learned that everything on your computer is a file in a folder with a path. A terminal doesn’t change any of that. It’s just a different way to talk to your computer about those files.

You already know the graphical way:

• Open Finder (Mac) or File Explorer (Windows).
• Double-click a folder to go in. Click the back arrow to go out.
• Drag, rename, delete with the menu.

The terminal is the same computer, the same files. You just type instead of click.

What you’ll actually see

When you open a terminal, you see a prompt. It looks something like this:

you@laptop ~ $

That’s the computer saying: “I’m waiting. Type something.” Everything before the $ is just information (who you are, what folder you’re in — that ~ is your home folder, from Lesson 0.5). The $ means “your turn.”

You type a command, press Enter, and the computer does it. That’s the whole loop.

Why bother learning it?

Three reasons people who type beat people who click:

• Speed. One line can do what twenty clicks do.
• Repeatability. You can save a command and run it a thousand times tomorrow.
• Reach. Most powerful tools — including Claude Code — are terminal-first. The terminal isn’t optional once you start using developer tools; it is the door.

How to open one

• Mac: press Cmd + Space, type “Terminal,” press Enter.
• Windows: press the Start button, type “Windows Terminal,” press Enter. (If you don’t have it, install it from the Microsoft Store — it’s free and made by Microsoft.)
• Linux: there’s almost certainly an app called “Terminal” in your menu. If not, press Ctrl + Alt + T.

Open one now. Look at the prompt. You’re not going to break anything by staring at it.

In the next lesson, you’ll type your first two commands.