Google Publisher Tag (GPT) is an ad tagging library with which you can dynamically build ad requests. GPT takes key details from you such as ad unit name, ad size, and custom targeting, builds the request, and displays the ad on web pages or mobile apps.
Now you can find more of what you're looking for on Facebook and discover fun connections between people, places and things.
Identifies administrators for a page which will be able publish data to your wall if you like any content within this page.
Google+ platform websites integration using the Google+ platform tag.
The Tweet Button is a small widget which allows visitors to share content and connect on Twitter.
Open graph description entity tag
Sites who has this tag are verfied by google to use WebMaster tools
A WebSite is a set of related web pages and other items typically served from a single web domain and accessible via URLs.