You've seen the dreaded Server not found: Your browser can't find the server at www.somedomain.com error. You check the URL (web address) you entered into your browser and it looks right but it just won't work. You may be a victim of the WWW Curse!
Most people learn the Internet the hard way, through the school of hard knocks and, most often, from what friends, social media and forum associates, and the geek next door, tells them. Sometimes the information is wrong; there's a lot of that going around! Sometimes it's right but the person then applies it to other situation where it's wrong. It's so confusing and there are few places to turn to get the right answers.
Whether it was through getting bad advice initially, or extending good advice to the wrong places, many people have learned to put a www. on the front of any domain name they are trying to use in a web browser. After all, doesn't www stand for world wide web and isn't that what your are trying to access with your browser?
Well, yes. And no. More confusion. To clear this up we first need to get a quick understanding of domain names. You know, the things that look like this:
somedomain.com
somedomain.net
www.somedomain.com
store.somedomain.org
There is a tendency to want to put a www. on the front of any domain that doesn't have one. Int the first two instances above that would probably (though not always) be correct. In the third it obviously isn't needed. In the fourth it would simply be wrong and likely result in the Server not found error.
The first thing you need to understand is that there is an exact purpose for domain names. They are what they are. The second thing is that computers read, or at least disect them, them from right to left. The right-most part of a domain, the .com, .net, or .org parts in our examples above, is known as the top level domain, or TLD.
There is a tendency for people to assume the TLD is .com (which is why it is better to get a .com TLD for your own domain) but these:
somedomain.net
somedomain.com
are not the same thing, nor are they necessarily the same place on the Internet. They might be if someone has purchased multiple TLDs in order to protect their brand. For example, these:
onlinesellersassociation.org
www.onlinesellersassociation.org
onlinesellersassociation.com
www.onlinesellersassociation.com
will all take you to exactly the same website. However, that's by choice, not just because. It could well be that each of the four go to different, unique websites.
In the domain name:
www.somedomain.com
the somedomain part is called the second level domain and the www part is called the third level domain. In this domain:
store.somedomain.com
the store part is the third level domain.
In its original design the second level domain would point to the server and third level domains would point to the various functions on the server. For example,
ftp.somedomain.com
would point to the file transfer process on the server located at
somedomain.com
and in this domain:
smtp.somedomain.com
would point to the mail transport process on the same server. Most people never saw these third level domains. Their file transfer software or their mail reading client took care of these and hid the configuration and the domains from the user. Then along came the world wide web.
Initially the www third level domain just pointed to the website on the server. The general rule was: one server, one website. That didn't last long. Sometimes, indeed most often these days, a single server will support multiple domains and each domain will have multiple websites.
In part because websites are now the most visible part of servers, both the second level domain and the www third level domain:
somedomain.com
www.somedomain.com
are usually configured to point to the primary website associated with that second level domain, but other third level domains such as:
store.somedomain.com
gallery.somedomain.com
blog.somedomain.com
and many others, may point to additional websites on the same server. These third level domains, often called sub-domains may, or may not (but typically not), support fourth level domains like:
www.store.somedomain.com
If they are not deliberately configured this way (and most are NOT) then adding the www. to the front of the third level domain will cause it to fail and result in the Server not found error.
A very popular third level domain:
stores.ebay.com
got so much traffic, and so many people adding the www. to the front, resulting in so many failures that the company programmed the fourth level domain:
www.stores.ebay.com
to go to the same place.
Personally I think this is wrong. When we accept errors and program to compensate we simply encourage users not to learn. The many people who make this fourth level domain error at eBay will go to other sites and expect it to work too. Instead of compensating for their error they should have been shown what was wrong and shown how to correct it. Learning the right way to do things, and understanding why, is a better way, I believe.
So, now you know that these
somedomain.com
www.somedomain.com
are not the same thing but are most typically configured to lead to the same place and, therefore, may be used interchangeably in most cases. These, however:
www.somedomain.com
store.somedomain.com
are not the same thing at all and will most often be configured to lead to entirely different places and adding the www. to the front of this:
store.somedomain.com
so it becomes this:
www.store.somedomain.com
is never the right thing to do, though some sites do compensate for the error making you think it is okay to do so.
Look for my other posts on the .com curse and the https curse.