HTML5 (HyperText Markup Language 5) is the latest version of the standard markup language used to create and structure web pages. It provides the foundation of every website by defining elements such as headings, paragraphs, images, links, forms, tables, and multimedia content. HTML5 introduced many new features, including semantic elements, native support for audio and video, improved form controls, canvas for graphics, and enhanced support for web applications. It works together with CSS3 for styling and JavaScript for interactivity to build modern, responsive, and user-friendly websites. HTML5 is widely used by web developers because it is efficient, flexible, and supported by all major web browsers.