Structured data for Website
Getting started with schema.org
Most webmasters are familiar with HTML tags on their pages. Usually, HTML tags tell the browser how to display the information included in the tag. For example, <h1>Avatar</h1> tells the browser to display the text string "Avatar" in a heading 1 format. However, the HTML tag doesn't give any information about what that text string means—"Avatar" could refer to the a hugely successful 3D movie, or it could refer to a type of profile picture—and this can make it more difficult for search engines to intelligently display relevant content to a user.
Schema.org provides a collection of shared vocabularies webmasters can use to mark up their pages in ways that can be understood by the major search engines: Google, Microsoft, and Yahoo!
You use the schema.org vocabulary, along with the microdata format, to add information to your HTML content. While the long term goal is to support a wider range of formats, the initial focus is on Microdata. This guide will help get you up to speed with microdata and schema.org, so that you can start adding markup to your web pages.
Source : http://schema.org/