HTML 5
<section>
<article></article>
<article></article>
</section>
HTML 4
<div>
<div></div>
<div></div>
</div>
Both of these have to be aligned by CSS. What exactly is the use of HTML 5? Yes there are form tags in HTML 5 that are very useful, but I’m concerned with the above.
One word: semantics.
See http://www.webmonkey.com/2010/02/building_web_pages_with_html_5/#Semantic_structure_at_last
EDIT: To paraphrase the article, by request (and rightly so), HTML 5 has added a set of new tags, such as
article,section,nav,header,footer, and others that have, traditionally, been created manually in HTML 4 by usingdivtags and semantic ID values (eg.<div id='header'>.By creating these new semantic tags, it allows for easier to understand markup for humans, as well as being easier to parse semantically by machines. For example, it will be easier to write code that crawls web pages looking for article content (think blog search) with a standardized tag, rather than having to search pages full of
divs.