FREQUENTLY ASKED QUESTIONS
A domain name is simply a textual address by which anyone can find your host machine on the Internet.
A domain name always contains a few components, i.e. labels, which are separated by a dot (period), thus: www.abc.com.my
The structure of a domain name conforms to the DNS Internet naming hierarchy which follows a tree structure. This structure allows computers to find each other on the Internet (see How are domain names translated into IP addresses?).
At the very top of this hierarchy is the root (which does not appear in the domain name). The next level down of this hierarchy is the top level domain (TLD), the one after that being the second-level domain, and so on.
The TLD is what appears at the far right end of a domain name. In the example above, the TLD is .my. TLDs come either as country codes domain names like .uk, and .jp, or generic top-level domain names like .com, .net, or .gov.
URL stands for Uniform Resource Locator, a form of address that specifies the location of an object, usually a webpage or a website on the Internet. Here are some examples of URLs:
A URL contains three parts, i.e.
Therefore, a domain name is used in a URL. When you use the web or send an e-mail message, a domain name is used. For example,
They are different forms of Internet addresses.
An IP address or network address is a numeric form of address that identifies every machine on the Internet. Therefore, every machine has a unique IP address. For example, the IP address of the abc company website could be 220.127.116.11.
A domain name is a textual form of address that is easier for humans to remember than the string of numbers that makes up an IP address. For example, the domain name of that same abc company could be http://www.abc.com.my. However, this domain name could have more than one IP address.
When you browse a particular web site, it is actually the IP address that determines the successful communication between your computer and the website. IP addresses could be said to be computer-friendly, while domain names are human user-friendly.
The technology that allows this to happen is called Domain Name System (DNS) technology. This provides the mapping between user-friendly domain names and computer-friendly numeric IP addresses. DNS is an Internet protocol and distributed database.
Here’s how DNS technology works. DNS comprises three components: the name server, the resolver, and the domain.
The hierarchical tree structure has these functions:
Take for example, the domain name www.abc.com.my. The Internet naming hierarchy for this domain is:
At the top of the DNS database tree are what are called root name servers. Each root name server knows the IP addresses of the name servers handling the top level domain names. In our example, the top level domain name is .my. If a querying name server would like to find out the IP address of www.abc.com.my:
The process is graphically presented below:
Example Query: What is the numeric address (IP address) of a machine with the hostname www.abc.com.my?
Example Response: 18.104.22.168
. (root) name server
remote name server <----> .my name server
- sends query to other name server
- gives response to client
<----> .com.my name server
| abc.com.my name server
remote DNS client (resolver)
- sends query to name server
Every domain name has name servers that handle queries for its information or records. What’s in a name server? It contains one or more DNS databases to store Internet hostnames and their associated IP addresses. DNS records need to be maintained by people.
Name servers are queried by various programs and other name servers to convert domain names into IP addresses all day long. Each name server, called a primary name server, usually has a back-up server, called a secondary name server, so that this can be done uninterrupted. Both primary and secondary name servers hold the authoritative data of a domain name.
If you wish to receive e-mail from the Internet you need to have a Mail Exchange (MX) record for your domain name in your DNS database. There are two ways to get name servers for your domain name: