FQDN

[Marquetta]

Stands for Fully Qualified Domain Name. An FQDN is a domain name that includes a hostname. For example, the URL www.techterms.com is an FQDN since it contains a hostname (www) and a domain (techterms.com). The domain name techterms.com is not fully qualified because it does not include a hostname.

An FQDN can be broken down into three parts:

A fully qualified domain name has the format [hostname].[domain].[tld]. The hostname can be used to specify different services and protocols for a single domain. For example, mail.example.com is often the required FQDN format when configuring the SMTP server for an email account. The FQDN ftp.example.com is commonly used when connecting to an FTP server. Name servers must be FQDNs and typically use the naming convention ns1.example.com and ns2.example.com.

Subdomains used as website addresses are also fully qualified domain names. For example, CNET uses the www.cnet.com as its main website address, but uses the subdomain download.cnet.com for its download hosting website. The FQDN download.cnet.com uses the same HTTP protocol as www.cnet.com, but directs visitors to a different website.

NOTE: Many websites no longer include www in their URLs and therefore are not fully qualified domain names.