What is meant by alphanumeric name

Understanding domains

The full name of a domain is saved as a Fully Qualified Domain Name (FQDN) designated. An FQDN indicates the exact position of a target computer in the tree hierarchy of the Domain Name System and consists of two parts: the Computer names (Host name) and the Domain name. The following example shows the FQDN of a fictitious mail server:


While mailserver represents the host name there example.com the domain under which the specific computer can be found. As Host name for servers that are responsible for the operation of websites, the characteristic is usually used www used:


It should be noted that the Fully Qualified Domain Name, unlike Internet addresses in everyday use, always ends with a period. This is the one hierarchical structure of the domain name system owed, according to which domains are always broken down starting from the highest level, the so-called root label.

Third level domainSecond level domainTop-level domainRoot label
www. example. com. (empty)

From right to left, the example domain is structured as follows: root label, top-level domain (TLD), second-level domain (SLD) and third-level domain. The FQND of www.example.com. thus includes four sections. In principle, however, domains can contain further subdomains below the third-level domain.