HTML tags are the building blocks of web pages, used to create and structure content. Each tag is enclosed in angle brackets, like this: <tagname>. Tags can define elements such as headings, paragraphs, links, and images. For example, the <p> tag is used for paragraphs, while the <a> tag creates hyperlinks. Tags often come in pairs, with an opening tag and a closing tag, like <tagname> and </tagname>. Some tags, known as self-closing tags, do not require a closing tag, such as the <img> tag for images. Understanding these tags is essential for working with HTML and building websites.