The document discusses how to add structured data or schema to web pages in order to provide metadata to search engines like Google. It explains that schema allows you to define content in a way that is readable to both humans and search engines. The document provides examples of adding schema using microdata to articles. It outlines the steps to define the schema format and assign properties. Finally, it discusses how adding schema through Google+ allows you to claim authorship of content and get rich snippets in search results.