Apps that link to your content can then use this metadata to deep-link into your app, take users to an app store to download the app, or take them directly to the web to view the content.
PHP is a widely-used general-purpose scripting language that is especially suited for Web development and can be embedded into HTML.
Allows a website to define how a page is rendered in Internet Explorer 8, allowing a website to decide to use IE7 style rendering over IE8 rendering.
Open graph description entity tag
The Open Graph protocol enables any web page to become a rich object in a social graph, a open protocol supported by Facebook
The average rating based on multiple ratings or reviews.
This page contains a meta robots tag which tells search engines and robots to index or not index the page.
Sites who has this tag are verfied by google to use WebMaster tools