Difference Between "description" and "og:description" in meta

Example of "description"

<meta name="description" content="description content">

Example of "og:description"

<meta property="og:description" content="description content">

"description" is for search engines which "og:description" if for Facebook's Open Graph. The generally accepted recommendation is to use both.

References:

• http://webmasters.stackexchange.com/questions/52600/should-i-have-ogdescription-and-meta-description-together-on-every-page
• http://www.sitepoint.com/forums/showthread.php?1103911-What-s-the-difference-between-meta-name-and-meta-property-og-description