With html5 the div for a page have been provided with consistent labels they are
|Tags||Page section useuage|
|<header> ... </header>||Page header the banding section at top of page|
|<nav> ... </nav>||Navigation usually under the header|
|<aside> ... </aside>||Any side information such as ads, blog links etc|
|<article> ... </article>||The main story of the page or the page section of the page|
|<footer> ... </footer>||The bottom footer on the page, usually has contact link, toss, etc|
The tags are just block elements and still need CSS styling to make them look more then just block elements. In HTML they are used to define what the tag/block is not what it looks like. CSS is needed to define the actual appearance of each element to the browser.