Dictionary of Computer and Internet Terms: ccTLD (country code Top Level Domain)
ccTLD (country code Top Level Domain)
a two-letter code indicating the country of an Internet address. For example, the web address for Oxford University is www.ox.ac.uk; here .uk is the country code for the United Kingdom.
Most codes can be used only for sites in the countries to which they belong. However, some countries, such as Tuvalu, encourage the use of their country codes elsewhere, so long as the country's own registrar gets the registration fees. For examples see .nu; .TV; .ws.