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What is the Domain Name System? by Sharlee Plett The domain name system is the backbone of the Internet, providing domain names for each web site address on the web. This article explains how the domain name system works in simple language. The Internet is made up of millions of computers all over the world that are connected together. Each of one these computers has its own set of numeric addresses, called Internet Provider or IP addresses. Particular file locations on particular machines (domains) are identified by their IP number. An IP address is made up of a series of numbers that are grouped into four blocks of numbers like this: 169.71.200.243. These numbers are assigned by Internet Service Providers (ISPs) when you sign up for web hosting. You may be assigned your own number or your ISP may provide you with a number that you will share with many other websites. If you have your own IP number, you have what is called a static IP address. If you share an IP address with other websites, you have what is called a virtual address. There's more to it than this, but for the purposes of this article, that's all you need to know. IP numbers were a workable addressing system when the Internet was small. Back then, everyone had a static IP address. But over the years, the Internet has grown astronomically and and with it the demand for IP addresses. To conserve IP addresses, virtual addresses came into use and the domain name system was created. IP addresses were problematic from the beginning because whenever you switched to a new host you were assigned a new IP address. You had to let everyone know your new IP address so they could find you again. The domain name system (DNS) solved both problems - the address changes and the huge growth of the Internet. The concept is simple - instead of a numeric address for your web site (domain), you use a domain name such as www.somesite.com. The domain name system was created to keep track of domain names and their current IP address. With the domain name system, when you type in www.somesite.com in your browser, the domain name system is accessed and the domain name is found in its files. The domain name system passes the current IP address to your computer. With the current IP address, you can locate and access the computer that website is hosted on. The domain name system has some great advantages - your web site's domain name stays the same no matter what IP number it currently has, it is a great deal easier for people to remember a name and the demand for IP numbers is greatly reduced by using virtual systems based on domain names. You can try out the domain name system using yahoo.com as an example: First type in www.yahoo.com and you'll be directed to Yahoo.Note: Once in a while Yahoo's IP address changes, so if the IP address above doesn't take you to Yahoo, you can always use a DNS lookup tool to find out what Yahoo's current IP address is. Here is a free online tool you can use: http://www.zoneedit.com/lookup.html. There is a great deal more to this technically (and that's an understatement!) but hopefully this will give you a good basic understanding of the domain name system. About the Author: Sharlee Plett is the webmaster of SmartWebCenter.com. A small business and web developer, her expertise includes database programming and accounting. |
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