secondary domain - Computer Definition
In the Internet Domain Name System (DNS), the rightmost portion of the address is the Top Level Domain (TLD), which identifies the type of entity owning or sponsoring the address, or the country in which the address is located. The several types of Top Level Domains (TLDs) include generic Top Level Domains (gTLDs) and country codes. The gTLD is always used. If a country code is also used in the address, it becomes the TLD and the gTLD becomes the secondary domain. See also country code, DNS, domain, gTLD, Internet, and TLD.