Open Graph is a standard for metadata that extends the normal information contained within a site’s head markup. This enables websites such as Facebook to display deeper and richer information about a website in a structured format. This information is then automatically displayed when users share links to websites containing OG metadata on Facebook.
<meta property="fb:app_id" content="123456789">
<meta property="og:url" content="<https://example.com/page.html>">
<meta property="og:type" content="website">
<meta property="og:title" content="Content Title">
<meta property="og:image" content="<https://example.com/image.jpg>">
<meta property="og:description" content="Description Here">
<meta property="og:site_name" content="Site Name">
<meta property="og:locale" content="en_US">
<meta property="article:author" content="">
<!-- Facebook: <https://developers.facebook.com/docs/sharing/webmasters#markup> -->
<!-- Open Graph: <http://ogp.me/> -->
<meta charset="utf-8">
<meta property="op:markup_version" content="v1.0">
<!-- The URL of the web version of your article -->
<link rel="canonical" href="<http://example.com/article.html>">
<!-- The style to be used for this article -->
<meta property="fb:article_style" content="myarticlestyle">
Twitter uses its own markup for metadata. This metadata is used as information to control how tweets are displayed when they contain a link to the site.
<meta name="twitter:card" content="summary">
<meta name="twitter:site" content="@site_account">
<meta name="twitter:creator" content="@individual_account">
<meta name="twitter:url" content="<https://example.com/page.html>">
<meta name="twitter:title" content="Content Title">
<meta name="twitter:description" content="Content description less than 200 characters">
<meta name="twitter:image" content="<https://example.com/image.jpg>">
<link href="<https://plus.google.com/+YourPage>" rel="publisher">
<meta itemprop="name" content="Content Title">
<meta itemprop="description" content="Content description less than 200 characters">
<meta itemprop="image" content="<https://example.com/image.jpg>">