What are Google backlinks

If you use a tool like xinu (ht tp://www.xinureturns.com/) to get your webpage information, there it shows stats for Google backlinks as well. What exactly are Google backlinks?

 

Go to www.google.com and in search bar write link:http://www.yoursitename.com the results which come is known as back links of that particular site..

 

if you type http://www.yoursitename.com , that's show you links to your site, but that's all not back links. But write link:http://www.yoursitename.com , then you can find out correct links.

 

There are better ways of checking backlinks IMHO.

 

basically backlinks are incoming links to your Website,
Google Backlinks are the Links which are listed in the Google Search which contains the Link to your Website.

 

Google backlinks are a small representation of your backlink profile. For some reason google no longer shows all links.

 

I think I still did not get it. If I do link:ht tp://www.yoursitename.com the result is ZERO backlinks.
But I with other tools I see there are backlinks. Also Yahoo is showing backlinks. So I am wondering why Google doesnt show any. Does it just take time till they show up or is there anything special about it.