What is canonical issue and how to resolve?
 

What is canonical issue and how to resolve?

The best and most effective way to resolve the canonical issue is with a permanent 301 redirect. This can be implemented in a number of ways, as detailed below. Depending on what server your website is hosted on will determine the method which you use to implement a redirect.
In addition to this it is worth also logging into Google Webmaster Tools and set-up two profiles for your domain; one with the www. prefix and one without. Then go to Site “Configuration> Settings> Preferred Domain” and choose which domain you would like Google to use.