HTML (HyperText Markup Language) is used for structuring the content of web pages. CSS (Cascading Style Sheets) is used for styling and layout, controlling how HTML elements are presented. JavaScript is a programming language used for adding interactivity and functionality to

Responsive web design is an approach to design and development that ensures a website's layout and content adapt to different screen sizes and devices. It's important because it provides a consistent and user-friendly experience across desktops, tablets, and mobile devices, improving accessibility and user satisfaction.

The DOM is a programming interface for HTML and XML documents. It represents the structure of a document as a tree of objects, where each object represents a part of the document, such as elements and their attributes. JavaScript can be used to manipulate the DOM dynamically, enabling interactions and updates on web pages without requiring a page reload.

CSS preprocessors like SASS and LESS are tools that extend the capabilities of CSS. They allow developers to use variables, functions, and nested rules, making CSS code more modular and maintainable. Preprocessors also enable code reusability and easier management of styles in large projects.