By adding microdata to the HTML code of your web pages, you can help search engines to understand the actual content of those pages. Microdata is a set of HTML tags that add structured information to text strings on the page. They explain, for example, that two words used on the page are a person's first name and surname, or that another string of words is that person's job title, or that a particular place mentioned on the page is an address, or a region, and so on.

Microdata isn't displayed on the web page, but it's read by search engines. By offering information (such as names and places) in a structured way, microdata allows search engines to interpret content and display it in a more meaningful way in search results lists. This gives a better preview of the sites listed. The idea behind microdata is that people searching the Web should find the content they're looking for easily.

Joomla 3.3 will automatically add microdata on your Joomla-powered site....