www or not?

sometimes some sites cannot be accessed without using the www. prefix in the url--and other times they can.

can anyone explain this??

thanks

It depends on the webserver configuration, DNS entries, and whether or not the admin knows what they're doing.

More than likely the administrator hasn't added a subdomain for "www".

Sometimes websites are also advertised for the wrong thing. My local public library signed up nearly 600 people for new library cards that had the web address starting with www before they realized the site started with http:// instead. Keep in mind that www means "world wide web." Also, some websites have been taken before people try to set up their domains so then they use .net instead of .com at the end because .com has been already taken.

You don't really need to use the http when typing in a url to the address bar, which is what 99% of the people at your library would be doing in order to access the library's web site.