Canonicalization is the practice of organizing your content so that every unique piece has one and only
Usually refers to home pages. For example, most people would consider these the same urls:
But technically all of these urls are different.
- Pick the url you want and use that url consistently across the site.
- Specify this url in Google Webmaster Tools site configuration > Settings > Preferred Domain.
- Make your webserver do a permanent redirect to the chosen url if you can. Otherwise use .htaccess file.
- Other than the .htaccess file there are more methods to do 301 redirect.
- You can check the redirect with webconf's Search Engine Friendly Redirect Checker