Difference between Yahoo backlinks and Google backlinks?

google Backlinks and Yahoo backlinks are "similar" but not all the same. It's easier to break it up into categories.

On the first category you have a Backlink, just a link on a site which directs to your site.

On the second category you have a dofollow link, a link which will be picked up by all search engines.

On the third category you have a nofollow link, a link which will not be picked up by some search engines.

google picks up dofollow backlinks only, Yahoo picks up both.