What does this mean?
It means automatically redirecting http://www.domain-name.com to http://domain-name.com.
There are many benefits of redirecting traffic from www to non-www.
The main advantage is, it will avoid duplicate content in search engines like Google. And it will also give a consistency to your website.
So how to implement this?
Just copy paste the below three lines in your .htaccess file.
RewriteEngine On
RewriteCond %{HTTP_HOST} !^domain-name\.com$ [NC]
RewriteRule ^(.*)$ http://domain-name.com/$1 [R=301,L]
Replace domain-name with your domain name.
Now your www traffic is redirected to non-www traffic.