The <main> element represents the dominant content of an HTML document.
It is intended for the central subject of a page or application—the content that is directly related to the document’s primary purpose. A page should generally have only one visible <main> element, and repeated content such as navigation menus, site headers, sidebars, and footers normally belongs outside it.
The element was introduced with HTML5’s semantic-structure improvements. Unlike <div>, which carries no inherent meaning, <main> tells browsers, search engines, assistive technologies, and developers what role that region plays. Screen readers can use this landmark to help users jump directly to the page’s principal content.
A common mix-up is choosing <article> or <section>. An <article> is a self-contained composition, such as a news story or forum post, while a <section> groups related content. Those elements may appear inside <main>; they do not replace its document-level role.