What is Top, Second & Third Level Domain Name

What is Top level Domain Name ?

A top level domain name is generally denoted to .com,.net and .org extension. A top level is also denoted as TLD. In the hierarchical domain system a top level domain occupies root zone of DNS(Domain name system). So every top level domain fills the first level of DNS zone also known as top zone or root zone.In 1980's, When DNS was designed, the Domain Name Space was given two division

1. gTLD
2. ccTLD

How TLD Domain Look Like

What is ccTLD ?

A ccTLD stands for Country code top level domains. A ccTLD mainly consists of 2 character territory codes.

What is gTLD?

A gTLD stands for generic Top level domain. A generic top level domain category was made to represent a set of categories domains ranging from different multi level organization. These multi level organization ranges from government sector, Education sector, Commercial sector, Military sector, Organization, Network and International sector.

• Top level domain for government sector - .gov
• Top level domain for Education sector- .edu
• Top level domain for Commercial sector- .com
• Top level domain for Military sector- .mil
• Top level domain for Organization- .org
• Top level domain for Network - .net

As the internet grew overtime, It become demanding to create additional generic top level domains. According to the sources in October 2009 there were 21 generic top level domains and around 250 two letter country top domains on the internet but as ICANN started a new policy towards naming domain names, It became possible to name new top level domains with new extension.

What is Second level Domain name?

A second level domain name is also called a lower level domain name. A second level domain name denoted with SLD occupies the second position in Domain Hierarchy system of DNS.
A second level domain comes just after Top level domain in the DNS. i.e. A second level domain assigns the left position after top level domains. e.g. Google.co.in here ".in" is the top level domain representing India while ".co" in the left of ".in" in the domain name Google.co.in represents a second level domain name.

What is Third level Domain name?

A third level domain name is the domain name which is writeen left to second level domain name. A third level domain name comes just after second level domain name.

Like third level domain there can also be fourth level domain and fifth level domain and so on. Each of these level domain name comes after one other and each of them are written on the left side one after the other. A typical example of a domain name with 4 level of doamin levels is "www.sos.state.oh.us".

 Here www stands for world wide web. "SOS" in the domain name is called the sub domain of "state.oh.us". "State" here also known as the sub domain name of "oh.us", "oh" is the sub domain name of "us" and last but not least "Us" here also means a top level domain name sub domain to "world wide
web".

We all know that domains names are registered keeping in mind either the name of the company, or product,or service.e.g. A company based domain name could be something like "Intel.com" or "hp.com" while a product based or service based domain name could be like "webhostingasia.blogspot.com" or even "gmail.com".

As discussed earlier that a domain contains a special componant in it which tells the web browser about the type of web server a query is seeking i.e. www.wallpaperdownload.biz could represent a web browser to seek an html file. while ftp:wallpaperdownload.biz could mean to seek ftp for document download. mail:wallpaperdownload.biz could mean to seek an email server.