301 redirect permanent.

301 redirect permanent runs on server side, We generally use 301 redirect to o fix canonical domain issue. For example we give preference to one domain with www. or without www so that search engines may not index same web page twice one with www (ie. www.toporganicseo.com) and second other without www (ie. toporganicseo.com/)

When our we page (s) is (are) indexed in both the form with www and also without www in that case search engines feels that our website is having duplicate web page (s) and our website is penalized so it is very important to put 301 redirect for our web pages.

If we don't like to put 301 redirection for our website then also we can fix this cannonical domain issue problem with google web master tool but only Google will follow your instruction some other major search engines like Yahoo, Bing will not consider and they may index our web page in both the form with www. and without www so it is better way that we put 301 redirection for our domain which will resolve issue in mostly all search engines

Redirecting With No www:

The sample code below will use Apache's mod_rewrite to redirect (R=301) your domain to the same domain without the 'www.' subdomain.

<IfModule mod_rewrite.c>
RewriteEngine on

# 301 redirect to domain without 'www.'
RewriteCond %{HTTP_HOST} ^www.example.com$ [NC]
RewriteRule ^(.*)$ http://example.com/$1 [R=301,L]
</IfModule>

Redirecting To www:

The sample code below will use Apache's mod_rewrite to redirect (R=301) your domain to the same domain with with the 'www.' sub domain.
<IfModule mod_rewrite.c>
RewriteEngine on

# 301 redirect to domain to 'www.'
RewriteCond %{HTTP_HOST} ^example.com$ [NC]
RewriteRule ^(.*)$ http://www.example.com/$1 [R=301,L]
</IfModule>

301 Redirect With Drupal:

For those of you with Drupal simply enter the lines below above the second 'chunk' of directives which wil be identical to your Drupal default .htaccess.
# 301 redirect to domain without 'www.'
RewriteCond %{HTTP_HOST} ^www.example.com$ [NC]
RewriteRule ^(.*)$ http://example.com/$1 [R=301,L]

# Rewrite current-style URLs of the form 'index.php?q=x'.
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule ^(.*)$ index.php?q=$1 [L,QSA]