In web development, HTML (HyperText Markup Language) serves as the foundational markup language for structuring content on the internet. It provides the basic framework for web pages, defining elements such as headings, paragraphs, images, and links. HTML organizes content in a hierarchy, utilizing tags to indicate how elements should be displayed in web browsers. Additionally, it enables integration with CSS for styling and JavaScript for interactivity, creating dynamic user experiences. Overall, HTML is essential for building and presenting web content effectively.