Domain names are the addresses of the internet. Every website on the internet is associated with an IP address that tells the browser where to find the website. Few people would be able to remember these numerical IP addresses, domain names are used to make it easier to navigate the web.
"What exactly is the domain name?" you might wonder. Consider the URL
http://www.example.com. The domain name is example.com.
Within the domain name, there is a hierarchical structure understood by web servers. The top most level of this hierarchy, known as the top-level domain (TLD), is the very end of the domain name. This part of the name generally indicates the type of organization that owns the website. Commonly used TLDs are .com, .net, and .org.
There is a loose standing of TLDs among internet users. Although .com is designated for commercial organizations in the United States, it is by far the most popular. Most webmasters consider .com to be the first choice of TLD. Internet users, as well, consider .com domains to have a higher standing than other TLDs.
The second most popular TLD is .net. Designated for internet related organizations and networks, .net is the second choice among webmasters. Other top-level domains include .org, .biz, .mil, .edu, and .gov.
Second-level domain names, SLD, are directly to the left of the .com or .net. In the domain, example.com, "example" is the SLD.
Author:
http://www.postdotcom.com (this is my site, please credit if redistributing)