How Does a Web Address Work?

by Bert Markgraf

Web addresses are domain names that let you find Internet sites and pages on the Web. The sites are on servers identified by their IP addresses. Domain names consist of words whereas IP addresses are groups of numbers and letters. Domain names are often easier to remember than IP addresses. The process by which your browser finds this material uses the domain name server system, which is the link between the domain names and their IP addresses.

Domains

A Web address consists of a domain name and instructions that come before and after it. Your browser recognizes the domain name by its standardized ending made up of a period with several letters to its right, such as .com or .net. The domain name includes characters to the left of the period and the ending. To the left of the domain name may be an additional period and a sub-domain name. To the right of the domain name might be a forward slash and folder or file names. The domain name gives the browser the name of the website and the additional instructions tell the browser where on the website's server to find particular images, pages or other material.

IP Addresses

The domain name doesn't tell the browser where on the Internet it can find the website. To find the server that is hosting a website with a particular domain name, the browser has to know the IP address. Every server that connects to the Internet has a unique IP address. Most common IP addresses are four groups of up to three numerals separated by periods, but newer IP addresses can have more characters and both letters and numbers. The browser has to find out which IP address it needs.

Domain Name Servers

Domain name servers have the IP addresses the browser is looking for. Every website has an associated name server. When you sign up for website hosting with your domain, the hosting service enters a record on its name servers regarding which IP address your domain will be using. When you register a domain name, you have to tell the registrar the names of your domain name servers. The registrar links your domain to the website's name servers and the name servers link it to the IP address.

Finding a Web Address

Domain registrars regularly give updates of their information to one of 13 root domain name servers. These servers have a record of every domain on the Internet and which domain name servers each domain uses. When you type a Web address into your browser, it asks the domain name server of your Internet service provider what IP address corresponds to the domain. If someone else has recently asked for the same domain, the name server still has the information and will switch your browser through to the correct website. If the name server doesn't have the information, it asks a regional server. If none of the local servers know the IP address, the root servers direct them to the correct name servers for the website. Those servers know the IP address and connect the browser to the website.

About the Author

Bert Markgraf is a freelance writer with a strong science and engineering background. He started writing technical papers while working as an engineer in the 1980s. More recently, after starting his own business in IT, he helped organize an online community for which he wrote and edited articles as managing editor, business and economics. He holds a Bachelor of Science degree from McGill University.

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