Meta descriptions are HTML attributes that provide concise explanations of the contents of web pages. Meta descriptions are commonly used on search engine result pages (SERPs) to display preview snippets for a given page.
Meta Keywords are a specific type of meta tag that appear in the HTML code of a Web page and help tell search engines what the topic of the page is.
The Open Graph protocol enables any web page to become a rich object in a social graph, a open protocol supported by Facebook
Google's hosted library for web fonts. Allows websites to choose and use fonts from a free, wide variety of fonts.