Little graphic next to URL

I am sure that this has been discussed before. But since I have no idea what it is called I can’t even do a search on it.

I did search using some keywords that I thought would find it, but nothing…

Anyway, I was wondering how this little grpahic that appears next to the URL (Safari). I.E. on CNN’ website, there is a little CNN in red right before the URL.

How is this accomplished? CSS? Anybody knows of any tutorials onhow to handle this?

Thank you very much for the help.

JH