What is a Domain Name?
A domain is a division of the Internet. Each domain is owned by a particular organisation, although some organisations own many different domains. For practical purposes, companies use unique domain names to make their websites easier to remember. The last three letters in a domain name are used to designate what type of organisation will be using a given domain (e.g. ".com" refers to a commercial interest ".gov" is the domain type for government organisations). A domain name remains the property of the owning entity until they stop paying the annual fee for its use or sell it to another organisation for a ridiculously inflated price...aah, capitalism.
What is a URL?
"Uniform Resource Locator" URLs are the textual or numerical addresses of specific pieces of information on the Internet. In order to access a web page, for instance, one must know the URL that corresponds with that particular page. Entering a URL to view a website is very much like dialling a telephone number to reach a company or individual.
What are Top Level and Second Level Domain Names?
TLDs are the names at the top of the DNS naming hierarchy. They appear in domain names as the string of letters following the last (rightmost) ".", such as "com" in "google.com". The administrator for a TLD controls what second-level names are recognized in that TLD. The administrators of the "root domain" or "root zone" control what TLDs are recognized by the DNS. Commonly used TLDs include .com, .net, .biz, .org, .info etc.
What are Subdomains?
Subdomain is a way to divide your site into sections with short and easy to remember names. For example, the client area portion of this site is https://manage.mdwebhosting.com.au/execute/base/listDomains