Anatomy of a prompt
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Anatomy of a prompt
1:50 · spoken companion to this lesson
In Module 1 you made Claude write a text file. Now you will make it build something you can look at: a web page about yourself, running in your own browser.
You do not need to know HTML. That is the point.
Set up
Open your terminal, go into the project folder you made, and start Claude.
cd my-first-projectclaudeYour first real prompt
Type this and press Enter:
make a file called index.html — a simple one-page website about me, with my name as a heading, a short paragraph about what I'm learning, and a list of three things I want to buildApprove it. Then leave Claude with /exit and open the file.
Opens the file in your default browser.
start index.htmlA web page. Yours. Made from one sentence.
Why that prompt worked
Look back at what you typed. It had three parts, and every good prompt has the same three:
| Part | In your prompt |
|---|---|
| Where | a file called index.html |
| What | a one-page site with a heading, a paragraph, and a list |
| Why | (you left this out — that is fine here) |
Compare it to what most people type first:
make me a websiteClaude will build something. It has to guess the topic, the sections, the file name and the style. You will spend the next ten minutes correcting guesses you could have prevented in ten words.
Where, what, and optionally why. That is the whole template.
The "why" earns its place later
The third part matters when Claude has to make a judgement call you care about:
in index.html, make the text bigger and darker, because I'm showing this to my grandmother and she finds it hard to readWithout the reason, Claude picks an arbitrary size. With it, it makes a sensible call — and it might do something you did not think to ask for, like increasing the line spacing.
Try it now
Start Claude again and change your page. Use all three parts.
in index.html, add a section at the bottom with a way to contact me, because I want to share this page with friendsOpen the file again. Read what changed.
What you just learned
- Claude Code can build things you can see, from one sentence.
- A good prompt names where, what, and sometimes why.
- Vague prompts are not faster. You pay for them in corrections afterwards.
Next: what "specific" actually looks like, on the page you just made.
Next
The specificity lever