Just a Few Files
Here’s a secret that makes everything easier: a website is just a few files.
When you visit a site, your browser (Chrome, Edge, Safari…) asks another computer for those files, downloads them, and draws the page from them.
The computer that holds the files and sends them out is called a server (a computer whose job is to serve files to visitors). It’s not magic. It’s just a computer that’s always on.
Visiting a website = your browser downloading a few files and drawing them.
Three Kinds of Files
Almost every web page is built from three kinds of files, each with its own job:
| File type | Its job | Think of it as |
|---|---|---|
HTML (.html) | What’s on the page: headings, text, images, buttons | The skeleton |
CSS (.css) | How it looks: colors, fonts, sizes, layout | The clothes |
JavaScript (.js) | What it does: reacting to clicks, animations, changes | The muscles |
A page with only HTML works, but looks plain, like a document from 1995. Add CSS and it looks designed. Add JavaScript and it does things.
You’ll Never Write These Yourself
Claude writes all three. So why learn their names?
Because now, when you ask for something, you know which layer you’re talking about:
- “Add a section about my hobbies” is an HTML change (new content).
- “Make the headings pink” is a CSS change (new look).
- “Make the photos zoom in when clicked” is a JavaScript change (new behavior).
And when Claude says “I updated the CSS”, you’ll know it changed how things look, not what’s on the page.
Static Sites: Just Files
A site that is only files, the same files for every visitor, is called a static site.
- A portfolio, a personal page, a small business site, a wedding invite: all perfect as static sites.
- Because it’s just files, hosting it is simple, fast, and often free.
That’s exactly the kind of site you’ll build in this course.
Static site: the same files, sent to everyone. Simple, fast, and free to put online.
Sites that are different for every visitor, like your email inbox or an online shop with accounts, need more machinery behind the scenes. That’s called a backend, and it’s saved for a later part of the course: Backends & APIs.