HTML is written in the form of HTML elements consisting of tags, enclosed in angle brackets (like), within the web page content. HTML tags usually come in pairs like


, although some tags, known as empty elements, are unpaired, for example . The first tag in a pair is the start tag, the second tag is the end tag (they are also called opening tags and closing tags). In between these tags web designers can add text, tags, comments, and other types of text-based content.

HTML tags can also be extended with attributes, usually name-value pairs, separated by “=” and written within the start tag of an element after the element’s name. These attributes help browsers and software systems to identify and address these elements and offer additional properties to manage their appearance.

Browsers and search engines do not display the HTML tags, but uses the tags to interpret the content of the page.Organizing the HTML’s tag in the correct hierachy help the search engines optimise index the website’s content correctly and accurately.