"A" record The DNS record that points a domain or hostname to an IP address

Cache The last results of looking to the authoritative servers for a give domain stored so that nameservers can respond more quickly to requests.

Cname A DNS record that points a domain or hostname to another hostname rather than a numeric IP address.

DNS Records The records kept on the nameservers that tell other machines online how to reach any given function of the domain.

Domain Name An alphanumeric name registered to an owner to point to email, web and other internet related services.

IP address The unique numeric identifier or address for any given connection online. Consists of 4 numbers from 0-255 seperated by a ".".

Minimum SOA The SOA record which controls how long local resolution nameservers keep DNS records on file before looking to the authoritative nameservers.

MX record Short for Mail Exchanger, the MX record is a DNS record specifying which mailserver is responsible for the domain.

Nameservers The machines which direct domain names to the IPs and servers that make them function. There are 2 ways nameservers are used. Authoritative nameservers keep the records for a given domain name which are the final authority on where it resides. Local resolution nameservers are the machines that look for a domain name when you try to access it through your ISP.

NS records Nameserver records which indicate which nameservers are responsible for the authoritative information about a given domain or IP range.

Propogation The process by which changes to a domains DNS settings are picked up through the internet.

Servers Machines responsible for a given function of a domain name, such as web hosting or email, are refered to as servers.

SOA (Start Of Authority) The Start Of Authority tells nameservers which nameserver is authoritative for the domain and contains information about how long to store information and other values which control how nameservers communicate about the domain.

TTL (Time To Live) Time To Live, another name for the Minimum SOA setting which controls how long non-autoritative nameservers keep information cached.

Registrar The company that handles the process of registering a domain name and maintains the whois record and rootserver entries for it. Usually the company the domain was purchased through.

Registry The company that maintains the definitive list of domains registered for all registrars to work with.

Root servers The set of servers which keep the definitive record of what nameservers are responsible for what domains, as well as details of the domains' registration status, which is refered to by nameservers when looking up domain names.

Whois record The file containing the ownership and contact information for a domain, as well as the nameservers authoritative for it. This record is maintained by the registrar of the domain, and filed with the root servers which are operated by the domain name registry.

Zone file The type of file that contains A records, SOA settings and other DNS information.