Apparently your host has set up a 301 permanent redirect from www to non-www. This is not the norm as most are doing it the other way around. That is not to say yours is incorrect. Someone, somewhere, decided that non-www was the way to go for you.
And what effect does this behavior have with SEO and G
Non-www presents some challenges out of the box. We've discussed them here in great detail over the years. I even made the decision to strip my WWW a while back and after a lengthy topic on the Pros and Cons, I changed my mind again. :)