Canonical Url is one of the main seo strategy for onpage optimization it helps search engine to avoid duplicate pages by selecting a correct url. Canonicalization solves the problem created by copied content pages and also important seo factor for boosting search engine visibility. It simply eliminates the duplicate urls by pointing a right unique content page of the website.
How to use canonical tag in seo
<link rel=”canonical” href=”http://www.domainname.com”>
Canonical tag helps to remove duplicate content pages of both www.domainname.com and domainname.com. Here you have to use canonical tag in duplicate page pointing a master content page. The canonical tag should be used in header section only. For example
<html>
<head>
<link rel=”canonical” href=”http://www.webluminous.com” >
</head>
<body>
</body>
</html>
Another method you can use 301 redirect for pointing a unique page content url from duplicate content page url. By this you can direct the search engine bots to crawl the right content page url. It also protects a website from google penalities.