This is a main and necessary tag of HTML5, without this tag you can't do anything in your HTML5 document. The body tag must be placed after the end of the head element inside the HTML element. The body tag is used for defining the body content of a document. The body tag helps render content in a browser. The body tag contains all the contents of an HTML document, such as HTML comment, button, text, paragraph, lists, image, audio, video, hyperlink, etc.