Rich snippets are an enhanced way of providing information about the type of content on your website to search engines.
For example, rich snippets can allow search engines such as Google to display product ratings on the search engine results page, such as the Google search engine listing for a product on www.lego.com highlighted at the bottom of the following screenshot (below the paid advertisements):
Rich snippets on the website allow Google to display the star rating for the product alongside the overall rating and number of reviews.
Tip
For more information on rich snippets, visit https://support.google.com/webmasters/answer/99170.
To implement the ratings-rich snippet, copy the summary.phtml file in the app/design/frontend/base/default/template/review/helper/ folder to app/design/frontend/default/m18/template/review/helper/, and open it to include the following highlighted code:
<div itemprop="aggregateRating" itemscope itemtype="http...