When you open a web page, your browser creates a virtual map of the page called the Document Object Model (DOM). The DOM is like a blueprint that the browser uses to display the content and structure of the page.
HTML (HyperText Markup Language) is the basic structure of the web page. It defines elements like headings, paragraphs, and images. For instance, <h1>Welcome!</h1> in HTML creates a big, bold heading on the page.
CSS (Cascading Style Sheets) is responsible for styling these HTML elements. It decides how they look, such as colors and fonts. For example, if you want the heading to be red and large, you use CSS like this: h1 { color: red; font-size: 48px; }.
JavaScript is the tool that makes your page interactive. It can modify HTML content and CSS styles dynamically. For instance, JavaScript can change the text of the heading when you click a button. Here’s how you might do that:
document.querySelector('h1').textContent = 'Hello, World!';
How They Work Together:
- HTML creates the structure of your web page and is represented in the DOM as nodes.
- CSS applies styles to these nodes through the DOM.
- JavaScript interacts with the DOM to change the HTML and CSS dynamically, making the page interactive.
Pro Visualization: Think of the DOM as a set of building blocks. HTML builds the blocks, CSS decorates them, and JavaScript moves them around or changes them when needed. For instance, if you have a button that, when clicked, should change the heading text from “Welcome!” to “Hello, World!”, JavaScript will make this change by directly interacting with the DOM.