If you notice, most of the websites are with www as prefix of the domain, i.e., www.rtfverterra.com and www.mathalino.com. This prefix of www for your domain name is not actually necessary for your domain name to work properly, meaning, you can go without the www prefix for your website. Check your website now, type www.example.com and example.com (replace example with your domain name of course) in different browser windows, make sure that you will not select any stored address in the address bar. If your website is accessible from two different address (with and without www), your site is not good for search engine optimization (SEO). Search engine will actually see this two address as two different websites, worst if your site will get penalize because of this. To avoid being penalize by search engine, all you need to do is to redirect one to the other. Here are the ways on how to do it.