Difference between Facebook link and source?

Question

I am trying to understand the difference between "link" and "source" in results from the Facebook opengraph API.

Example #1 (the common case): 'link', but no 'source'

{"id":"538094606_148946261795695","from":{"name":"Shameem CK","id":"538094606"},"picture":"http://external.ak.fbcdn.net/safe_image.php?d=b916dff3b3d53ac29d8a3c3b97e3895a&w=90&h=90&url=http%3A%2F%2Fwww.vodafone.in%2Fvodafone%2Fmisc%2Fsep10.jpg",
"link":"http://www.vodafone.in/vodafone/misc/sep10.jpg",
"name":"http://www.vodafone.in/vodafone/misc/sep10.jpg","caption":"www.vodafone.in","icon":"http://static.ak.fbcdn.net/rsrc.php/z2E5Y/hash/8as8iqdm.gif","type":"link","created_time":"2010-08-27T14:13:02+0000","updated_time":"2010-08-27T14:13:02+0000"}

Example #2: useless 'link', 'source' has more info

{"id":"1786294159_109521125771227","from":{"name":"Dan Inspire","id":"1786294159"},
"link":"http://www.facebook.com/",
"source":"http://www.youtube.com/v/IY3U2GXhz44&autoplay=1",
"name":"Google I/O 2010 - Keynote Day 2 Android Demo - Full Length","caption":"www.youtube.com","description":"Google I/O 2010 - Keynote Day 2 Android Demo    For all I/O 2010 sessions, please go to http://code.google.com/events/io/2010/sessions.html","icon":"http://static.ak.fbcdn.net/rsrc.php/z9XZ8/hash/976ulj6z.gif","type":"video","created_time":"2010-08-27T10:57:09+0000","updated_time":"2010-08-27T10:57:09+0000","likes":1}

Ideas about how to choose the best one (of link and source) to display for a user to click on?

Answer 1

Link is the url to an object, this is usually applied to images. Source is used for media objects such as videos