TLD stands for "Top Level Domain" and is the last part of a domain name. Top-level domains are managed by the IANA- "Internet Assigned Numbers Authority" (the authority for assigning names and numbers in the Internet). These are of three types: • national domains (ccTLD - country code TLD): used by countries or dependent territories. They are two letters long, for example .ro for Romania. • Generic domains (gTLD – generic top-level domain): used (at least theoretically) by certain categories of organizations (for example, .com for commercial organizations). It has three or more letters. Almost all gTLDs are available regardless of country, with the exception of .gov and .mil domains, which for historical reasons are only used by governments and the military respectively. • infrastructure domains: .arpa is currently the only such domain.