What Is the Meaning of ".Com" & ".Net"?by Steve Lander
The ending few letters of a domain name are called top-level domains. Two of the most popular are .com, which stands for "company," and .net, which stands for "network." The TLDs are part of the Internet's domain system which provides a hierarchical name that people can use and remember. The name then maps to a numerical address that the computers that make up the Internet use.
The Seven Original TLDs
In the 1980s, seven top level domains were created. Three were open to anyone that wanted to register them -- .com, .net and .org, with the last being developed for non-profit organizations. In addition, four more limited domains were set up. Government agencies could use .gov, the military could use .mil, Internet organizations used .int and .edu was reserved for educational institutions.
At the same time, each country got its own two-letter country TLD, usually based on its country code. The United States, for example, got .us, and many cities, counties and states eventually set up their websites using it. For example, Marin County, which sits across the Golden Gate Bridge north of San Francisco, originally used co.marin.ca.us as its domain name. Some two-letter codes have become popular outside of their host country. Tonga makes money selling the right to create a site with a domain name ending in .to, while the .tv country code has nothing to do with television. It's the code for the island nation of Tuvalu.
With the dawn of the 21st century, names in the most popular TLDs like .com and .net started getting harder to find as more and more were registered. The Internet Corporation for Assigned Names and Numbers responded by both creating new TLDs like .biz and by creating a system to allow even more names to be created. While, as of the date of publication, none of the existing new names have caught on to the extent of .com or .net, ICANN continues to support adding new domain names, and the dominance of .com could change.
TLDs, Domains and DNS
The TLD is just part of a domain name. Different names get broken down in different ways. For example, in the UK, a business might register its name as business.co.uk while a college would use school.ac.uk, where the two-letter code between the name and the .uk tells you more about the type of site. However the name gets structured, a directory assistance program called the domain name service stores a database that connects names to a numeric or alphanumeric Internet Protocol address. For example, when you plug "google.com" into your Web browser, it looks the name up in the DNS, and finds out that it actually needs to go to one of a block of addresses including 18.104.22.168.