|  | 15.2 | Domain Name System
| 15.2.2 | The domain name server
The domain name server (DNS) is a device on a network that manages domain names and responds to requests from clients to translate a domain name into the associated IP address. The DNS system is set up in a hierarchy that creates different levels of DNS servers. If a local DNS is able to translate a domain name into its associated IP address, it does so, and returns the result to the client. If it cannot translate the address, it passes the request up to the next higher-level DNS on the system, which then tries to translate the address. If the DNS at this level is able to translate the domain name into an associated IP address, it does so, and returns the result to the client. If not, it sends the request to the next higher level. This process repeats itself until the domain name has been translated, or the top-level DNS has been reached. If the domain name cannot be found on the top level DNS, it is considered to be an error and the corresponding error message is returned. Any type of application that uses domain names to represent IP addresses, uses the DNS to translate that name into its corresponding IP address. -
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| DNS: The Domain Name System