Domain Name

Domain name (called d omain name) - a unique identifier for a specific node (device or network connection), part of the Internet, the name of the website. It is composed of letters, digits and "-" sign (provided that he is not at the beginning or end of the name). Now may be the use of diacritical marks.

Domain names are easy to remember addresses to nodes and spread them
network resources (websites, blogs, social networks, mail servers,
etc.). All domain names are functioning thanks to the DNS (Domain Name System - The Domain Name System).

The structure of domain names

A domain name consists of a number of separate domains, separated by periods. For example, the full name google.com, second-level domain includes Google, a part of the first level domain com. There are some restrictions on the length of the domain name. Full name should not exceed 63 symbols. Nevertheless, in some countries allowed to register domain names up to 127 characters.

The hierarchy of domain names

Domains zero (Root Domain - tree root domain) - marked with an empty domain name. For example, in the name somesite.com. domain is zero after the last dot. These blank label with zero length are supported only on the main nodes in DNS.

Higher level domain (TLD called - Top-Level Domain) - is the most important, the domain zero, text labels. These domains can not be bought.
According to the classification, managing them IANA (Internet Assigned
Number Authority), they are divided into the following types:

Basic domain

1. Functional domains (called Generic Top-Level Domain, gTLD):
   
   
   • not sponsored higher level domain (com, net, org, biz, info, name, pro);
   
   
   • Links domains of higher order (ace, int, aero, cat, coop, eco, jobs, mobi, museum, post, phone, travel, xxx);
   
   
   • limited use domain (edu, gov, int, mil);
   
   
   • the infrastructure of the Internet domain (arpa, root);
   
   
   • reserved domain (example, invalid, localhost, test).
   
   
   
   


2. Country code TLDs (called Country Code Top-Level Domain ccTLD):
   
   
   • domain, consisting of a two-letter country code, according to ISO 3166-1 STANDARD (uk, us, uk);
   
   
   • 
     internationalized domain (called Internationalized Domain Names, IDN)
     containing the characters of national alphabets (Cyrillic, Hebrew,
     Arabic, etc.), for example рф, бг, ભારત.
   
   
   
   

Pseudo
(called pseudo-domains) - they are not used by the DNS system, and are
used to transfer such as Electronic mail to computer networks with
different addressing scheme. Examples include local or BITNET.

Unused domain now: nato, web, CSNET, DDN.

Alternative and additional domains of higher order
- the former are created using alternate DNS servers (eg Namecoin,
Pacific Root, dotBERLIN, etc.) and additional domains are generated
using a special software.

The proposed domain of higher order - their introduction to DNS is scheduled for next time.

Second-level domains (called the Second-Level Domain, SLD) to identify domains, which marks the full name of the domain facing the domain name of a higher order. Often, a second-degree domain names of companies, which include the page.
For example, in the domain name apple.com domain of the second degree
is Apple (company name), and this domain belongs to the first level
domain com. An example of a domain can be a third-degree technology in the full name technologie.gazeta.pl. It belongs to the second-level domain newspaper, which in turn belongs to a first-degree pl.

Domain names and IP addresses

In DNS, domain names can transform into IP addresses and vice versa. In this way, the IP can be based on the domain name of the node on the basis of a name - IP. One domain name can correspond to a single IP address, or more of them (if you work for one address several servers).
One IP address can correspond to one or more domain names (if the
registered owner of the server or the server several addresses available
to different clients).

Commercialization of domain names

Easy-to-remember domain names, particularly valued the Internet, they are widely used for commercial purposes. Regardless of domain names have not yet been covered by intellectual property rights. The greatest commercial potential, characterized by all of the basic domain and some of the national domain of a higher order. Renowned also czteroznaczne domain belonging to the second level domain com.
The domain name market is such a phenomenon as cybersquatting,
involving the registration of prospective names (eg, identical with the
names of well-known trade marks, company or just easy to remember) for
subsequent resale.