Domain Name Servers (DNS)
Introduction
With millions of computers connected to the Internet and billions of web sites, they all need to be organised. The Internet achieves this by a system of IP addressing and Domain Name Servers.
IP addresses and domain names
Each website on the Internet has got its own unique IP address, or Internet Protocol address. 204.75.342.16 is an example of what an IP address looks like. People prefer to use words rather than numbers so many computers are called by a domain name. For example, Microsoft.net is the domain name of the Microsoft Corporation. The bbc's domain name is bbc.co.uk. Many organisations will also buy up all of the other Domain name extensions to protect themselves from people setting up spoof sites which look like they are legitamate. The BBC, for example, has also bought up the domains bbc.com, bbc.info, bbc.org and so on. However, behind each of these domain names, there is an IP address.
Domain Name Servers (DNS)
When you want to go to the web page for the BBC, you type the domain name into the URL search area on your web browser and press 'Enter' on your keyboard. The domain name is intercepted by a 'Domain Name Server' or DNS that your Internet Service Provider has. The job of the domain name server is to look up in its database the domain name you have typed into your web browser and find the matching IP address. It then forwards the request onwards, using this address. If it cannot find the IP address in its own database, it then contacts other Domain Name Servers until it finds it, or if it can't find it anywhere, it displays a 'web site not found' message to you. When the request reaches the destination, the pages are sent back.
Uniform Resource Locator (URL)
The 'URL' is the fancy name for a full website address. An example of a URL is http://www.theteacher.info Three pieces of information are contained in a URL; these are the protocol, the domain name and optionally, the file to display. For example, the URL http://www.bbc.co.uk/news would take you to the news web page, at the domain name www.bbc.co.uk using the communications transfer protocol http.
Registering Domain Names
Each domain name is unique. To use a domain name that is still available, you must register it with a company set up for that purpose. You then effectively rent that domain name for as long as you want it. It is not particularly expensive - you can register your own .co.uk domain name for a few pounds per year (or a domain name with any other ending, such as .biz or .com for example). Many of the easily remembered domain names have already been taken but you can try searching e.g. www.reg-123.co.uk This is a typical website that sells domain names. You can search for domain names to see what is available, see how much they cost and register those that you want. Try searching for a domain name associated with your own name or for an imaginary business.