The more information a search result snippet can provide, the easier it is for users to decide whether that page is relevant to their search. With rich snippets, webmasters with sites containing structured content—such as review sites or business listings—can label their content to make it clear that each labeled piece of text represents a certain type of data: for example, a restaurant name, an address, or a rating.
Providing this information doesn't affect the appearance of your content on your own pages, but when Google crawls your site, we’ll recognize markup for the following information types: reviews, people profiles, products, recipes, music, and events. (In addition, developers can use their own custom data markup 
).
Programmable Search Engine will use this information to create rich search results snippets that improve the search experience for your users.
Here's an example of a recipe snippet that includes review information. (Check out live examples on our test site. )
You can enhance your search results in two ways. You can use either, or both—pick the option that works best for your content.
- Use meta tags to identify key information in your documents.
- Use rich snippets markup inline in your HTML. This option also enables rich snippets in Google Web Search.
- Add PageMap data to your HTML page. This option enables you to add actions (such as a Download link) or custom attributes to your snippet.