You can view all the scematic mark up by visiting http://schema.org
What good does it do?
Well, rather than have a web page full of text and the standard title and meta info to give search engines, you can have a page full of specific markup that will tell search engines, and machine readers alike, exactly what that text is about. Look at the product listing on any given osCommerce category page. What do you see? Products of course. But what does the S.E. see? Unless it is microformatted, they see not much more than title tags and some simple text.
Once you equip a page with microformats, you can test the markup using the Google Rich Snippets Testing Tool, http://www.google.com/webmasters/tools/richsnippets
Here is a preview of what the testing tool shows us for the default osCommerce categry, DVD Movies > Comedy :
Extracted rich snippet data from the page Item Type: http://schema.org/webpage breadcrumb = Top → Catalog → DVD Movies → Comedy Item Type: http://schema.org/product image = http://XXXXX/images/dvd/theres_something_about_mary.gif url = http://XXXXX/product_info.php?products_id=19 name = There's Something About Mary offers = Item( 1 ) model = DVD-TSAB manufacturer = Fox aggregaterating = Item( 2 ) Item 1 Type: http://schema.org/offer price = $49.99 pricecurrency = USD availability = http://schema.org/InStock Item 2 Type: http://schema.org/aggregaterating ratingvalue = 5 bestrating = 5 reviewcount = 1 Item Type: http://schema.org/product image = http://XXXXX/images/dvd/youve_got_mail.gif url = http:/XXXXX/product_info.php?products_id=7 name = You've Got Mail offers = Item( 3 ) model = DVD-YGEM manufacturer = Warner Item 3 Type: http://schema.org/offer price = $34.99 pricecurrency = USD availability = http://schema.org/InStock
As you can see, the category page is now listed as a webpage, located in the category specified by the breadcrumb, that holds multiple products, with the name of the product, links to the product image, and page, the model, manufacturer, price, currency, stock value, and when a review is available, the average value and review count is also displayed.
And there is more, this is only the surface, microformatting can also add more to the search results and even be used for building your sites own custom search engine.