There are a lot of different domain names available for registration. If you need a domain name for a website with an international audience, one of the international domain names approved by ICANN will be the natural choice. For web sites targeting a country, the top level domain (tld) of that country is recommended. There are also some country-specific domain names that are usable for international web sites.
The most common international domain names are:
.com is the safest choice and can be used by almost all web sites.
.net a was originally meant for network organizations and .org was meant for non-profit organizations, but they can be used for all kinds of web sites.
.info and .biz are newer tld domains (launched in October 2001) for general information and business web sites, respectively. They have not been as successful as the corporations behind them hoped for and the corresponding .com domain name is a safer choice for most web sites (if available).
.co.uk is a tld for the UK and as such is a good choice for UK based sites.
Some country-specific domain names that can be used by web sites with an international audience, are .ws (World Site), .tv (for tv channels) and .cc. Some of these domain names are more expensive, and can have different pricing schemes and registration rules.
Warning!
New.net and various other 'registrars' sells domain names that are not approved by ICANN, like .chat, .game, .kids .shop etc. While these domain names may look good, and most of them are not registered yet, web surfers need a plugin to view your site and search engines will not be capable of registering your website. Do not buy one of these domain names to use it as the primary address of your website. However there is a small possibility that these domain names will be ICANN-approved in the future, so it may be possible to snap up domain names that could become valuable if they are approved by ICANN in the future.