Social plugins are tools that other websites can use to provide people with personalized and social experiences. When you interact with social plugins, you share your experiences off Facebook with your friends and others on Facebook.
The main social plugins include:
Like button: Click Like to publicly share and connect with content from other websites that you find interesting. Learn more.
Send button: Click Send to share a link and optional note as a private Facebook message, Facebook Group post, or email. Learn more.
Comments box: Publicly comment on another website using your Facebook account.
Activity Feed: What your friends are liking, commenting on or sharing on a site.
Recommendations: Most liked content among your friends on a site.
If you're a developer, learn more about implementing these features within a single line of HTML.
While social plugins appear on other websites, the content populating them comes directly from Facebook — so they're just an extension of your Facebook experience. Plugins were designed so that the website you are visiting receives none of this information.
You only see a personalized experience with your friends if you are logged into your Facebook account. If you are not already logged in, you will be prompted to log in to Facebook before you can use a plugin on another site.
At a technical level, social plugins work when external websites put an iframe from Facebook.com on their sites, as if they were agreeing to give Facebook some real estate on their websites. When you visit one of these sites, the Facebook iframe can recognize if you are logged into Facebook. If you are logged in, it’ll show personalized content within the plugin as if you were on Facebook.com directly. Even though the iframe is not on Facebook, it is designed with all the privacy protections as if it were.
Watch this video to learn more about the Like button you see on other websites and how social plugins let you take your friends with you around the web.