FQDN, Fully Qualified Domain Name

A fully qualified domain name is essentially the name for a web server. It consists of a hostname proceeded by the full domain name. For instance, the FQDN for a email server may be: yourmail.theschool.edu. In this scenario, the hostname is yourmail and is found within the domain name: theschool.edu. For the example above, .edu acts as the TLD (top-level domain). A TLD is comparable to the root directory on a basic workstation from in which all other directories originate. An organization can be assigned within the TLD of a domain and have the authority to create other sub-domains within it. The same rules apply for a web address. For example, www.theschool.edu would be a fully qualified domain name. In this scenario, www. represents the name of the host within the theschool.edu domain. Using an SSH client to make a connection requires an FQDN to be specified. A DNS server will match a hostname to an IP address by referring to it’s DNS table. From there the host is contacted and the user receives a prompt to login.