Top-level domains

[Sudhakar]

Every domain name ends in a top-level domain (TLD) name, which is always either one of a small list of generic names (three or more characters), or a two-character territory code based on ISO-3166 (there are few exceptions and new codes are integrated case by case). Top-level domains are sometimes also called first-level domains.

The generic top-level domain (gTLD) extensions are:

Generic   .biz · .com · .info · .name · .net · .org · .pro
Sponsored   .aero · .asia · .cat · .coop · .edu · .gov · .int · .jobs · .mil · .mobi · .museum · .tel · .travel
Infrastructure   .arpa
Deleted/retired   .nato
Reserved   .example · .invalid · .localhost · .test
Pseudo   .bitnet · .csnet · .local · .root · .uucp · .onion · .exit

A country code top-level domain (ccTLD) is an Internet top-level domain generally used or reserved for a country or a dependent territory.

Vanity ccTLDs are TLDs which are used for various purposes outside their home countries, because of their name. For example,

.ad is a ccTLD for Andorra, but has recently been increasingly used by advertising agencies or classified advertising.
.ag is a ccTLD for Antigua and Barbuda and is sometimes used for agricultural sites. In Germany, AG (short for Aktiengesellschaft) is appended to the name of a stock-based company, similar to Inc. in USA.
.am is a ccTLD for Armenia, but is often used for AM radio stations, or for domain hacks (such as .i.am).
.as is a ccTLD for American Samoa. In Denmark and Norway, AS is appended to the name of a stock-based company, similar to Inc. in USA. In Czech Republic, the joint stock corporation a.s. abbreviation stands for Akciová společnost.
.be is a ccTLD for Belgium, but is sometimes used for the literal term "be".
.cc is a ccTLD for Cocos (Keeling) Islands but is used for a wide variety of sites such as community colleges, especially before such institutions were allowed to use .edu.
.cd is a ccTLD for Democratic Republic of Congo but is used for CD merchants and file sharing sites.
.ck is a ccTLD for Cook Islands was notably abused in Chris Morris's Nathan Barley by preceding it with ".co" in order to spell out the word cock (.co.ck as in trashbat.co.ck).
.dj is a ccTLD for Djibouti but is used for CD merchants and disc jockeys.
.fm is a ccTLD for the Federated States of Micronesia but it is often used for FM radio stations (and even non-FM stations, such as internet radio stations).
.gg is a ccTLD for Guernsey but it is often used by the gaming and gambling industry, particularly in relation to horse racing and online poker.
.im is a ccTLD for the Isle of Man but is often used by instant messaging programs and services.
.in is a ccTLD for India but is widely used in the internet industry.
.it is a ccTLD for Italy but is used in domain hacks (e.g. .has.it).
.je is a ccTLD for Jersey but is often used as a diminutive in Dutch (e.g. "huis.je"), as "you" ("zoek.je" = "search ye!"), or as "I" in French (e.g. "moi.je")
.la is a ccTLD for Laos but is marketed as the TLD for Los Angeles.
.li is a ccTLD for Liechtenstein but is marketed as the TLD for Long Island.
.lv is a ccTLD for Latvia but is also used to abbreviate Las Vegas or less frequently, love.
.ly is a ccTLD for Libya but is also used for words ending with suffix "ly".
.md is a ccTLD for Moldova, but is marketed to the medical industry (as in "medical domain" or "medical doctor").
.me is a ccTLD for Montenegro, and is recently opened to individuals.
.ms is a ccTLD for Montserrat, but is also used by Microsoft for such projects as popfly.ms.
.mu is a ccTLD for Mauritius, but is used within the music industry.
.ni is a ccTLD for Nicaragua, but is occasionally adopted by companies from Northern Ireland, particularly to distinguish from the more usual .uk within all parts of the United Kingdom
.nu is a ccTLD for Niue but marketed as resembling "new" in English and "now" in Scandinavian/Dutch. Also meaning "nude" in French/Portuguese.
.sc is a ccTLD for Seychelles but is often used as .Source
.sr is a ccTLD for Suriname but is marketed as being for "seniors".
.st is a ccTLD for São Tomé and Príncipe but is being marketed worldwide as an abbreviation for various things including "street".
.tk is a ccTLD for Tokelau but is bought by someone and given away at dot.tk page
.to is a ccTLD for Tonga but is often used as the English word "to", like "go.to"; also is marketed as the TLD for Toronto.
.tv is a ccTLD for Tuvalu but it is used for the television ("TV") / entertainment industry purposes.
.ws is a ccTLD for Samoa (earlier Western Samoa), but is marketed as .Website
.vu is a ccTLD for Vanuatu but means "seen" in French as well as an abbreviation for the English language word "view".
.vg is a ccTLD for British Virgin Islands but is sometimes used to abbreviate Video games