UNDERSTANDING THE SEMANTIC LAYOUT IN HTML5
The new semantic layout in HTML5 refers to a new class of elements that is purely designed to help you understand where and how text is defined in your web page and its context. All semantic tags must appear within the <body>...</body> container tag group.
Each semantic element has no specific output, color, or design; they are purely here to help you, the web developer, understand the context in which HTML code and text belong on your page. Each element can be stylized with CSS, however, which is described later in the section “Assign CSS Styles to Layout Elements.” Until then, each element will be invisible, and its text will appear drab and monotone when viewed in an HTML5 web browser.
It is important ...