Domain name space

Definition
Domain name space is

"[a]n Internet addressing scheme that is hierarchical in nature and uses a "tree" structure to organize information that describes networks and computers. The domain name space is the sum total of domain names that currently represent networks and computers, as well as all of the possible domain names &mdash; not yet in use &mdash; which may potentially represent networks and computers. Also, the realm of networks, computers, and other network devices that can be described and represented by the Domain Name System (DNS)."