Current versions of the most popular Web browsers do not require http:// to be entered in the address field when surfing the Internet. However, whether or not a website will require www. is not dependent on the browser, but on the Domain Name System (DNS) record for that domain.
Web surfing is made possible by a massive cooperative effort based upon a common language or set of protocols. All computers connected to the Internet follow these protocols in order to be able to communicate with one another. When a surfer clicks on a hyperlink or manually enters an address in his or her browser, it connects to the DNS database to look up the relevant DNS record. The record contains the name of the website, such as www.wisegeek.com, and the corresponding numerical address, known as the Internet Protocol (IP) address. Every computer on the Internet must have a unique IP address so that pages can be sent by Web servers and received by surfers.
Some DNS records only contain one version of the domain name. For instance, a DNS record might only contain www.example.com, and not example.com. In this case if a surfer enters the latter, no match will be found and the browser will hang or come back with an error message. If the surfer amends the address to www.example.com, the DNS record will be found. Now the browser will obtain the IP address and connect to the host server to request the desired webpage.
Many domains today are created without “www.” preceding the address, negating the need to enter it into the browser. The DNS record for such a site will list the domain name as, example.com. Nevertheless, some surfers will add the “www” prefix out of sheer habit. To route this traffic as well, the DNS records of these sites commonly include an extra entry called CNAME. This tag allows one to map an alias to the main domain name. The alias, in this case, would be the longer, “www.example.com.” With this type of DNS record, a surfer reaches the site whether or not “www.” is entered.
DNS records can be amended to include a mapped alias. If the site was created as a subdomain on a host server named "www" it may only contain www.example.com in the DNS record. If you would like to amend the DNS record to catch all intended traffic, contact your domain registrar.