Does Google see www.example.com and example.com differently?

www vs root again

[jweighell]

I have mainly been promoting my site as www.example.com. Recently I had one in-bound link that just used example.com. Since then, all of my Google SERPs seem to just be going to example.com from this one link. Is this going to affect my positioning?

My PR has gone to 0 recently, although I wonder if this is just Google tinkering with their algorithms?

[Marcia]

There are a number of PR0 homepages now, even with interior pages having decent PR.

And no, www and non-www are not the same. www is technically a sub-domain, and it's wise to use .htacess to do a permanent redirect from example.com to www.example.com if that's what you choose to use.