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 layout, colors, fonts, spacing, and overall visual appearance of web pages, allowing developers to separate content from design.
JavaScript is a versatile, high-level programming language primarily used to add interactivity and dynamic behavior to web pages. It runs in the browser and can manipulate the DOM, handle events, make asynchronous requests, and much more. It is an essential part of modern web development.
Responsive design is an approach to web design that makes web pages render well on a variety of devices and screen sizes. It uses flexible grids, flexible images, and CSS media queries to adapt the layout to the viewing environment, ensuring a consistent user experience across desktops, tablets, and smartphones.