An Internet domain is a collection of data describing a self-contained administrative and technical unit on the Internet, according to the principles of the DNS system. This data can comprise the address of a computer, a resource or a service on the domain (www, e-mail, FTP), the name and address of the DNS server, security data for DNSSEC and more. Global visibility of an Internet domain is provided for by the DNS service.
An Internet domain name is a textual designation registered by a user for their own use, meeting administrative and technical conditions for the visibility of the Internet domain under that name. At the time of registration, the name is entered into the central registry database, which is administered by the Internet domain Registry. An Internet domain name becomes active once the registration data are entered, including data on the DNS servers, into the DNS table of the central registry database and that table is made active on public DNS servers. Internet domain names were traditionally written using the letters of the English alphabet (ASCII code), but with the development of the IDN standard the possibility has now been established for domain names to be written in other world languages and scripts. An Internet domain name is comprised of a series of alphanumeric segments, separated by full stops, complying with Internet standards. A segment can contain numbers (0-9), letters of the English (or some other) alphabet (a-z) and hyphens (-), and the length of a segment cannot be shorter than two or longer than 63 characters. A segment cannot contain a hyphen at the start or the end, or two consecutive hyphens as the third and fourth characters.
In simple terms, the Internet domain is part of a system in which Internet addresses are linked to specific locations on the Internet – servers, websites, e-mail servers etc. An Internet domain name is your own Internet address which you have registered as part of a national or international Internet domain (e.g. the Internet address rnids.rs within the .RS domain). It is an integral part of a website and e-mail address and thus identifies you on the Internet. In everyday use the term “Internet domain” is also used when referring to an Internet domain name.