We used HTML so we can define headers , paragraphs , links , images , and more , so your browswer knows how to sructure the web page you're look at.
We will use javaScript to allow users interaction with the web pages. like show or hide more information with the click of a button , changing the color of a button when the mosue govers over it and many more.
We used CSS because it gives web pages their look and foramtting. In other words, CSS is what you use to make sites look nice with fancy fonts , rich colors , gorgeous backgrounds, and even slick animations and 3D effects.