New Feature Rendering Pages With Fetch as Google

The Fetch as Google feature in Webmaster Tools provides webmasters with the results of Googlebot attempting to fetch their pages. The server headers and HTML shown are useful to diagnose technical problems and hacking side-effects, but sometimes make double-checking the response hard: Help! What do all of these codes mean? Is this really the same page as I see it in my browser? Where shall we have lunch? We can't help with that last one, but for the rest, we've recently expanded this tool to also show how Googlebot would be able to render the page.
Viewing the rendered page

In order to render the page, Googlebot will try to find all the external files involved, and fetch them as well. Those files frequently include images, CSS and JavaScript files, as well as other files that might be indirectly embedded through the CSS or JavaScript. These are then used to render a preview image that shows Googlebot's view of the page.

You can find the Fetch as Google feature in the Crawl section of Google Webmaster Tools. After submitting a URL with "Fetch and render," wait for it to be processed (this might take a moment for some pages). Once it's ready, just click on the response row to see the results.

Fetch : Only fetching html not rendering 
Fetch and Render: Fetching and rendering

For read at : http://googlewebmastercentral.blogspot.in/2014/05/rendering-pages-with-fetch-as-google.html