It exists "www" in URL or doesn't exist (Method of union to either)

It might not be in the case there to be www in the Internet address. It thought about the meaning of www and the usage. (You should be or you should not exist www, and unified method of the URL.)

Meaning of "www"

"www" is originally abbreviation of World Wide Web. This puts on all over the world like the cobweb and is Hypertext system (HTTP) of the Internet that they are made to come round. The Hypertext system shows that the character string in the document has linked with another text and the file.

When the user of the Internet transmits URL to a browser, the command to acquire the connection and the web page to the web server by HTTP is transmitted. If the file specified by the transmission exists, the file of specification is sent from the server.

Originally, the subdomain existed like "www." "ftp." "mail." because it had divided the server by each server like the Web server, the FTP server, and the mail server, etc.Therefore, it is possible to hook up to the Internet even if there is no "www." now though there was "www." after "http://" like seem being natural it in old times.

"www" is a subdomain.

Dot ".", the alphabet, and the figure ahead of the domain are called a subdomain. When this subdomain has adhered, it is considered another site in the search engine.

The alphabet and the figure slash "/" and afterwards after the domain are called a subfolder (subdirectory), and this is considered in the same site.

It is more convenient to be able to display the page even if there is www or it doesn't exist.

It is very inconvenient when thinking that it is possible to connect it at time alone without can the connection only at time with www, and www from the side used. Being possible to connect it in a word even if there is www or it doesn't exist is more convenient.

However, it is considered another page thus as described later in the search engine. The effect of the link decreases if put on both of links. It becomes disadvantageous on SEO because it becomes a page not to follow the policy of Google that the page of the same content is not opened to the public with different URL.

Then, it is possible to connect even if there is www or it doesn't exist, and there is www or uniting it to either no cervine is the best.

Setting of server that can be accessed regardless of presence of "www"

The homepage was not able to be displayed by "http://www.sample.jp/" by the homepage's being displayed only by "http://sample.jp/" in Xrea.com and the Coreserver.jp server that I had been using.

It is a method of registering "www" as a subdomain to display it by both. In a word, "www.sample.jp" is registered in the subdomain by setting the domain.

Because the homepage is displayed by both "http://sample.jp/" and "http://www.sample.jp/", it is convenient as it is. However, it becomes disadvantageous on SEO. In a word, it is considered another site in "There is www" and "There is no www". Moreover, when two or more sites of the same content are made, both of both might not be registered by the retrieval.

To prevent this, as follows is done in the server of Xrea.com and Coreserver.jp. It is set that "http://www.sample.jp/" is forwarded to "http://sample.jp/". However, this method confirmed becoming 302 moves.

"There is www" and "There is no www" are united with htaccess by 301 forwarding.

Both "http://www.sample.jp/" and "http://sample.jp/" URL that shows the same content might exist. Thus, it is considered another page in the search engine.

The effect of an external link decreases if put on both of links of the outside. It becomes disadvantageous on SEO because it becomes a page not to follow the policy of Google that the page of the same content is not opened to the public with different URL.

Then, it unites it to either of URL of "There is www" and "There is no www". In a general server, forwarding is set by using 301 redirecting of htaccess.

Even if the domain is forwarded, information on the site in the move origin that the search engine recognizes is succeeded to the site of the new address. 301 redirecting is the methods of moving the domain that the search engine recommends.

Setting method of 301 redirecting

From "www.sample.jp" to "sample.jp" with 301 redirecting is set as follows, and describe it in the file ".htaccess"

When uniting it with www

Options +FollowSymLinks
RewriteEngine on
RewriteCond %{HTTP_HOST} ^sample\.jp
RewriteRule ^(.*)$ http://www.sample.jp/$1 [R=301,L]

When uniting it without www

Options +FollowSymLinks
RewriteEngine on
RewriteCond %{HTTP_HOST} ^www\.sample\.jp
RewriteRule ^(.*)$ http://sample.jp/$1 [R=301,L]

Which is good when there is "www" or when it is not?

Both are also the same even if there is "www" on the web or it doesn't exist. I think that one with few four characters of "www." is good in various respects. Time when one that is even one character less inputs the character can decrease, and the disk space at preservation be also a little.