Given the amount of industry noise about native video and scripted animations, you’d be forgiven if you had never heard of the new microdata specification included in HTML5.
Similar to outside efforts like Microformats, HTML5′s microdata offers a way of extend HTML by adding custom vocabularies to your pages.
The easiest way to understand it is to consider a common use case. Let’s say you want list details about a business on your page — the name, address, telephone number and so on. To do that you’ll need to use some vocabulary in addition to HTML, since there is no
Using microdata, you can create your own custom name/value pairs to define a vocabulary that describes a business listing.
When a search engine spider comes along, it will know that not only is your data a business listing, but it can discover the address, the phone number, or even the precise geo-coordinates if you want to include them.
Given that HTML5 is still a draft at this point, why bother?
Actually, despite its lack of publicity and HTML5′s still-incomplete status, microdata is already being used by Google, which has started adding information gleaned from microdata markup to its search result snippets.