"A" record 
This is used to point a domain to a specific IP address.

Administrative contact 
The contact recorded on the name's record who is responsible for the administration of the address.

Stands for country code Top Level Domain; e.g. .AU. These extensions, of which there are 255, always have two characters. While most ccTLD's are associated with a country, some nations have relinquished control to other registries and are able to be registered by anyone, anywhere; e.g. .tv (which was associated with the island nation of Tuvalu).

The practice of registering a name for the specific purpose of preventing another party from doing so, usually with a goal of either damaging the other party, diverting traffic from that party or selling it to that party for an inflated price.

Stands for Domain Name System, which is essentially the internet's address book that translates numbers (IP addresses) into more human-friendly addresses 

Domain Name
A domain name is a sequence of letters and/or numbers/hyphens separated by one or more periods (".") that act as a pointer to a unique numerical internet protocol (IP) address. 

Dropped domain
A domain where the registration, grace and redemption period has expired and the name is again available for anyone else to register.

The date on which the registration period for a name ends. 

The last two or three letters of a domain name after the final "." This signifies the registry (and sometimes the country - see ccTLD above) it is associated with.

The practice of registering a domain and then quickly selling it quickly for a profit. This may involve developing a basic site first, or just selling it as is.

The banned practice of a registrar using sensitive information such as searches to determine what names to register, with view to reselling them at a higher price. 

Grace period
The period during which a registrant can renew a domain after it has expired before it becomes available to register by others. 

Stands for generic Top Level Domain - gTLD's include .com, .net, .org

Another term for cybersquatting (see above)

Internet Corporation for Assigned Names and Numbers. ICANN plays a coordination role of the Internet’s naming system.

Stands for internationalized Domain name - these are names that contain character/s of a language-specific script.. 

IP Address 
A unique set of numbers identifying a resource on a computer network, including the internet.

Keyword domain 
A website address consisting of words related to the service or product it represents. While this once lent significant weight to rankings in Google, that is no longer the case. Still, keyword domains can be a good idea due to the relevancy, recognition and resale potential aspect. 

A web server that acts as a directory for resources such as web sites on that or another server.

The practice of pointing a name to a placeholder page, which may also include advertising and/or an invitation to make an offer on the address. 

Propagation window 
The period of time between changes being made to a domain name record and those changes being distributed (propagated) throughout the internet. The propagation window is anything up to 24 hours and is out of the control of the registrar as ISPs update their DNS caches at different times.

Redemption period 
The timeframe after the grace period in which a domain name can still be renewed by a registrant after it has expired (but renewal will usually cost much more).

The person or party with control over a domain name and is listed as such on the name's record.

An acrredited organistion/business that provides domain registration services to the public. 

The body that controls and manages top level domain (TLD). 

The term associated with extending the registration period of a domain name.

An agent or affiliate of a registrar that provides domain name services.

Reverse domain hijacking 
When the owner of a brand attempts to gain control of name legitimately registered by another party through false claims. 

Root server 
A name server for the root zone of the internet's Domain Name System (DNS)

Second level domain (2LD)
An extension that is directly below a TLD. 

A domain name consisting of multiple words with a character sequence that when put together can be interepreted to mean something else - sometimes with embarassing results. 

A separate address under a domain name, e.g. test.example.com

Where a party uses a brief period to test the potential for a domain and then requests a refund on unwanted names.

Technical contact 
The contact responsible for technical aspect of the control over a website address.

Stands for Top Level Domain, examples include .com, .net, .org, .info.

The term used to describe the reassigning of control of a domain name to another party, who then becomes the recognised registrant.

Typo domain 
A mispelled name used to try and capture traffic resulting from a wrong address being typed into a browser.

Uniform Resource Locator - the address of a specific web page. 

A query system for determining registrant contact and other details associated with a domain name.

Zone file 
A file on a server containing mappings between domain names and IP addresses.