You are basically... well, see for yourself:
example
When you do link:
www.link.com you are basically clicking on the:
Find web pages that link to
www.rhinosgirls.com
When you do link:
www.link.com you are doing:
Find web pages that contain the term "www.rhinosgirls.com"
This site is like 5 or 6 days old so it isn't the best example but I think it illustrates my point well enough.