So far we have talked about what we call frontend development.

We’ve used HTML and CSS to create Web Pages.

We then learned JavaScript, and how to use JavaScript to interact with the browser.

Now it’s time to take a look at the server side, the backend.

JavaScript can also be used outside of the browser, in what we call server runtimes. In this unit we’ll study Node.js, the most popular and important one. Other runtimes exist, like Deno or Bun.

Node.js is a runtime, a tool, that allows us to run JavaScript outside of the browser.

This means we can use JavaScript to run programs that run on our computers, or on servers.

Node.js also powers most of the JavaScript tooling, as we’ll see.

It’s worth noting that in the frontend, inside the browser, the only language we can use natively is JavaScript. That’s the only language the browser knows.

But on the server, we could use any language. Ruby, PHP, Python.. the list is long.

JavaScript however is a great choice because instead of learning multiple languages, you can learn JavaScript and use it everywhere. There’s less context switching. You can get very good at JavaScript and be proficient with it in both frontend and backend.

We’ll use Node.js extensively, explicitly or abstracted by other tools that are built on top of it, to:

• listen for data sent by forms
• create an API
• work with databases

…and much more.

It is a central part of everything in Web Development, so it’s essential you understand it well.

Lessons in this unit: