The Internet domain name system (DNS) consists of a directory of all the domain names and their corresponding computers registered to particular companies and persons using the Internet. When you register a domain name, it will be associated with the computer on the Internet you designate during the period the registration is in effect.
Note that the above description applies to domains that are registered and hosted. If the registrant elects to, a domain can instead be registered and parked. A parked domain name does not need a DNS affiliation.