Domain redirect
The domain has to be redirected from http://domain.com to http://www.domain.com to stop content duplication.
This has to be done by creating the .htaccess file in the root folder.
creating .htacces file is very simple.
Open a notepad or any text editor copy paste the following code
Options +FollowSymlinks
RewriteEngine on
rewritecond %{http_host} ^yourdomain.com [nc]
rewriterule ^(.*)$ http://www.yourdomain.com/$1 [r=301,nc]
in that above code modify yourdomain then save the file as .htaccess without any filename
upload the .htaccess file in your root directory.
That is it. Your domain has redirected.