When you want to access a website on the Internet, you have to type in the website's URL, or Uniform Resource Locator. This URL is the specific address of the website, and thus lets your computer find that site. A URL might look like:
The "www.thinkquest.org" part of the URL is the domain name. Domain names tell the computer where to look for the server of the website. Domain names can refer to specific computers, organizations, companies, or other entities. There are four levels of domain names:
1. Top-Level Domains:
Second-level domain names can have up to 61 characters. They must be unique to the organization that registered it. Two organizations cannot have the same second-level domain name.
3. Third-Level Domains:
In addition to the top level domain names listed above, every country in the world has its own unique top-level domain name. For example:
Domain Name Server (DNS):
As you know, every single computer that is connected to the Internet has a unique IP Address. This address identifies the specific computer for all of the other computers connected to the Internet.
Domain names must be translated to an IP Address in order for computers to be able to communicate and exchange information. All domain names have a corresponding IP Address. We could just type in the numbers instead of this corresponding IP Address instead of the domain name, but who could possible remember a long string of numbers? Names like www.yahoo.com, www.amazon.com, and www.google.com are so much easier to remember! In addition, sometimes the IP Address of a particular domain name might change.
When you first get on the Internet, and you type in the URL: http://library.thinkquest.org/C0115420/,
the first thing that happens is that the DNS will change "www.thinkquest.org"
into the numbers of the IP Address. Then, the file will be transferred from
the ThinkQuest server to your computer for you to view!
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