Google search engine sees www.domain.com and domain.com as
two different domain. So, you might get duplication error message in Google
analytic or webmaster tools.
To fix this duplication, you can redirect all www to non www
with .htaccess files.
Let's get started. Open Notepad or any plain text editor.
Insert this code to your file and save it as .htaccess
without any extension:
RewriteEngine On
RewriteBase /
RewriteCond
%{HTTP_HOST} ^www.(.*)$ [NC]
RewriteRule ^(.*)$
http://%1/$1 [R=301]
The finally upload this .htaccess file to your website root
folder.