HTML5 structural elements and SEO
HTML5 comes with few nice structural tags that can really help in SEO and reduces <div> tag clutter. The word SEO covers a large hidden treasue, hidden beacauss google (and others) search engines never reveales how some websites rank up to their first page but there is still many areas of website developement that can be helpful in better SEO and HTML5 has added few more things
The Navigation Tag
When it comes hyperlinks no one wants them to be ignored by search engines specially google, So why not to highlight the important links of your site.Though google will most likely index almost all hyperlinks but its always a good idea to tell “Hey! google buddy these and these are important links please don’t ignore them!”
HTML5 specifies a <nav> tag. If you are serious about SEO, wrap-up your important links inside Navigation tag
Header , Footer and Article
HTML5 specification adds simple (but important in SEO perspective)<header> , <article> and <footer> tags.Articles based websites blogs,news consists – Header,content and Footer.Header section specifies title of article whereas footer may consist authors name.<Header> , <Footer> and <Article> tags help bots differentiate between article’s header ,footer and main content.
Google has not yet revealed anything how he sees these tag but in most likely scenarios search engine crawlers will use these tags to understand web page content.Google search result(other too) show snippets of webpage so wrapping up your content in article tag might be good idea.
As header and footer are structural elements so these can also be used with table headings or overall heading of page.
header footer tag HTML5
In plain words <aside> tag refers to sidebar you see on right of this post. As per HTML5 Specifications, if <aside> tag is used inside an article tag ,content of aside should be related to article but if used outside content in aside tag should be related to website as whole. <aside> tag is a good way to include hyperlinks of related content in your article or separating other links from articles.