HTML stands for HyperText Markup Language. It is the standard markup language used to create and structure content on the web. HTML describes the structure of a web page using a series of elements, which tell the browser how to display the content.
CSS stands for Cascading Style Sheets. It is a stylesheet language used to describe the presentation of a document written in HTML. CSS controls the layout, colors, fonts, and overall visual appearance of web pages, separating design from content.
JavaScript is a versatile, high-level programming language that enables interactive and dynamic behavior on web pages. It can manipulate the DOM, handle events, make asynchronous requests, and much more. JavaScript is an essential part of modern web development alongside HTML and CSS.
Responsive design is an approach to web design that ensures web pages render well on a variety of devices and screen sizes. It uses flexible grids, layouts, images, and CSS media queries to adapt the presentation of content to the viewing environment, providing an optimal experience for users on desktops, tablets, and mobile phones.