The glossary below contains many of the terms you will find in common use throughout the Symantec Security Response website. Please refer to this list to find definitions of terms and answers to other Internet security-related questions.

FQDN fully qualified domain name

An unambiguous domain name that specifies the exact location of a computer within the domain's hierarchy.

The complete domain name for a specific computer, or host, on the Internet. The FQDN consists of two parts: the host name and the domain name. An example is

A URL that consists of a host and domain name, including top-level domain. For example, is a fully qualified domain name. www is the host, symantec is the second-level domain, and .com is the top-level domain. An FQDN always starts with a host name and continues to the top-level domain name, so is also an FQDN.