www.http and http

[cindi]

What is the difference between having a site that is http://www and one that is http://sitename

Thanks
Cindi

[troyzone]

Hi Cindi,

There really isn't any difference between www.sitename.com and sitename.com it's just that www stands for World Wide Web and it has been a convention for years for that to be placed at the beginning of Internet home page addresses, so people are used to doing it.

In most cases, a web host's DNS server configuration contains DNS name to IP address mappings for one's account containing both www.sitename.com and sitename.com, so the domain name will resolve to the IP address leading to one's hosting account either way. In other words, whether the www. is included is usually optional.

The one catch is often a visitor's browser will cache or "remember" each version of a page separately, so for instance you may see a different version of the page when using www. as opposed to no www. In such a case, only one version is actually the correct page...the other one is from the browser displaying an older, cached copy of the page. Refreshing the browser should yield the correct page in such a case. For a past example of this happening to someone here, see this thread:

erichw33.proboards53.com/index.cgi?board=web&action=display&thread=1174664271&page=1#1174692032

In that case, the member was seeing two different pages when he used the www and no www. He never responded back to confirm, but I'm sure his browser was just showing him a cached page and refreshing the browser should have made them both appear the same in the end by showing the most up-to-date version of the page stored on the web host.

For an explanation of how DNS in general works, see the following thread:

erichw33.proboards53.com/index.cgi?board=web&action=display&thread=1149944847&page=1#1150061140

It's an old post and there are a few other specific issues discussed there, but the overview of DNS still applies. Hope this helps.

Troy