What JavaScript is — and what you can build
The language of the web
Every website is built from three languages that work together:
| Language | Job | Like a house… |
|---|---|---|
| HTML | The content and structure: headings, text, buttons, forms | The walls and rooms |
| CSS | The look: colours, fonts, layout | The paint and furniture |
| JavaScript | The behaviour: what happens when you click, type or scroll | The electricity and plumbing |
Where JavaScript is used
- Websites and web apps — online shops, social media, Google Docs, games
- Servers — with Node.js, JavaScript also runs the "back end" of many apps
- Phone and desktop apps — tools like React Native and Electron use JavaScript
Learning JavaScript opens doors to web development, IT support, testing, data and many other tech jobs — and the thinking skills of coding help in any job.
What coding really is
Coding is giving a computer very exact instructions. Computers are fast but not clever: they do exactly what you say, in order. Most of coding is breaking a problem into small steps — and fixing things when they don't work. Getting errors is normal. Every developer gets them every day.
What you'll build in this course
Get your starter files
This lesson has a download attached: JavaScript course starter files. It contains a playground page for practising, exercises and solutions for each module, and the two projects. Download it and unzip it somewhere easy to find, like your Documents folder. You'll set everything up in the next lesson.
Try it
Think of an app or website you use every day. Write down three things on it that JavaScript probably does (for example: "the Like button changes colour when I tap it").
Downloads
2 files to download once you enrol.