Incorporating structured data into your site
I decided to take advantage of the new, built-in, RDF support in Drupal 7. I spun up a new site, enabled the RDF module, and starting digging around the administration panel to see where I could control what it was doing. And I found … nothing. It turns out that adding RDF support to your site is more than a matter of simply enabling the RDF module. To get the best use out of it, you need a little additional information, and most likely another module or two.
The Drupal community has long discussed the need to make Drupal sites a vital part of the Semantic Web by adding structured data to the html. There are various ways to do that, using RDFa or microformats or microdata, and there has been lots of discussion about which would be better. Drupal 7 was finally released with RDFa support built in, and that functionality is extended by several contributed modules.