What will be your answer if we ask you to give the website name for Google? Well, there is a substantial likelihood of you saying the Google website name as ‘www.google.com’.
This is how you may be remembering some of the important sites that you frequently access, i.e., by their names. It may not be technically correct to call this as a website name.
Are you wondering why?
So, what is this called?
Well… when you type ‘www.google.com’ in your browser, you are actually typing a domain name. It is though domain names that you would find a site. This is why domain names are also referred to as web addresses. So, google.com is the domain used for Google’s website.
Now let’s learn about a domain name.
What is a Domain Name?
A domain name is nothing but an identification of the website IP address of the server where the website is hosted. Every website has a unique identification name or label known as the ‘domain name.’ There is no fixed definition of a domain name.
If you were to draw an analogy in real life, a domain name is like an entry in a phone directory that helps people to find you and connect to you by dialing the phone number listed there.
Similarly, in the internet world, a domain name is a representation of numerically addressed Internet resources. These resources could be anything such as networks, computers or services. The registry (similar to phone directory) in which the domain names are listed is known as the DNS (Domain Name System).
A domain name is a label for a location where you will be able to find certain information or activities. You can refer ‘domain names’ as ‘domains’ as well.
Functions of a Domain Name
The main purpose of a domain name is to act as a label for indicating ownership of a resource. It represents the host name in the URL. For example, ‘www’ is the hostname in ‘www.abc.com’.
A domain name may point to several IP addresses to enable server redundancy for the services. This is helpful in managing the load on large and popular websites.
The aim behind using a domain name is to get an identifiable name for the relevant internet resource. This helps in addressing that resource. You can move the resource to a different physical location within your address network.
A company can use its own name as the domain name so that its customers can find it on the internet. You can use the domain to represent your industry, your family name, your brand, and so on.
Domain Name Space
It is the logical and hierarchical tree structure naming system, which forms the basis of DNS. Every node in this tree holds information corresponding to the domain name.
The Internet Corporation for Assigned Names and Numbers (ICANN) manages the top-level architecture of the DNS. The domain name registrar helps in the registration and the reassignment of domain names. For registering your domain name, you need to avail the services of a registrar by paying a certain amount. The ICANN authorizes these registrars for such activities.
Domain Name Syntax
A domain name comprises of several components put together along with delimitation by dots. The components are labels that denote particular internet resources or their attributes. Now, let us study this domain name example to decode the syntax and list some rules:
- The domain name system is not case sensitive. But, it is a common practice to write domain names in the small case.
- The domain name hierarchy flows from top-level to sub-levels, from right to left. For example, www.google.com. Here, ‘com’ represents the top-level domain. ‘Google’ represents a sub-level domain. And, ‘www’ is the sub-domain of the ‘google.com’ domain.
- The tree of labels may go up to 127 levels, and the complete domain name text may not exceed 253 ASCII characters.
- In the above example, ‘www.google.com’ and ‘google.com’ are also hostnames. This is because they have an IP address with them.
- A hostname has some limitations on the characters in its name.
- A hostname is always a domain name, but a domain name may not always be a hostname. For example, ‘com’ is not a hostname, as it does not have an IP address.
Top Level Domains (TLDs)
The top-level domain is the first-level set of domain names that form the DNS root zone. Some examples of the generic top-level domains are com, org, net, info, gov, edu, etc. For all domains in the lower levels, a TLD is the last label of a fully-qualified domain name. For example, in the domain name www.google.com, the top-level domain is com.
Even the country code top-level domains (ccTLDs) are included in this set. These ccTLDs are two-character abbreviations for various countries. For example, ‘.in’ for India, ‘.au’ for Australia, and so on. Every domain name ends with the top-level domain name, as it is always the rightmost part of any domain name.
The responsibility for managing the top-level domains is given to specific organizations by the Internet Corporation for Assigned Names and Numbers (ICANN). The ICANN operates the Internet Assigned Numbers Authority (IANA) and maintains the DNS root zone.
Second Level Domains
Second-level domain is located below a top-level domain in the DNS hierarchy. The second-level domain name always appears on the left of a top-level domain. For example, in www.google.com, Google is the second-level domain of the .com TLD.
The second-level domains commonly refer to the name of the organization that registered the domain name.
Third Level Domains
A third-level domain is the next level after the second-level domain in the DNS hierarchy. It always appears to the left of the second-level domain. For example, in www.google.com, www is the third-level domain of the .com TLD. The third-level domain usually indicates an individual server inside a company.
Though it is not mandatory to include a third-level domain, using it can make the domain names more intuitive.
International Domain Names (IDN)
In the DNS, you can take advantage of the ASCII (American Standard Code for Information Interchange) character set. It does not permit the use of labels or names in native scripts of many different languages such as Arabic, Chinese, etc. But, ICANN has given approval for the IDN system.
An IDN is an Internet domain name that contains, at least, one label, which is displayed in software applications. This label could be in whole or in part. It could also be in a language-specific script or alphabet, such as Arabic, Chinese, or the Latin alphabet-based characters with diacritics. IDNs are stored in the DNS as ASCII strings using Punycode transcription.
Fictitious Domain Names
Certain domain names are used for fiction or popular culture (film, media, etc.). In reality, that domain may not exist. These domain names are either invalid or unofficial TLDs. For example, ‘example.com’ is a fictitious domain name.
Domain Name Registration
Apart from ICANN, an administrative organization maintains and services every top-level domain name.
This organization maintains the database of domain names that are registered for the top-level domains. Every authorized domain name registrar assigns names in the relevant top-level domain. This registrar also passes this registration information to the registry. The registry publishes this information using a service known as the ‘WHOIS’ protocol.
As a customer, you get the right to use a domain name for a limited duration. During this period, you have to pay to your domain name registrar for keeping this domain name. You become the registrant of the domain name registrar.
Technicalities Involved in the Domain Registration Process
As a registrant, you can assign an administrative contact to control the domain. This contact will manage information such as postal address, contact info, billing information, etc. This contact will conform to the domain registry requirements for using the domain name.
You can also assign a technical contact to manage the name servers for your domain name. As part of your registration service, the registrar offers you two or more name servers.
As a registrant, you may specify your own name servers to host a domain’s resource record.
Domain Name Reselling
Many registrants do not use all the registered domain names. Some of them use this as a business opportunity. They resell the registered business names, either at a set price or through bidding.
This type of domain name reselling is called domain aftermarket. The higher the demand for a particular domain name, the greater could be their price.
Some registrars may also be willing to pay any amount for a particular domain name of their choice.