What is a domain?
Domain name means which in essence corresponds to the physical address of your website. Think of a navigation satellite, for example. In order to provide you with the necessary directions, it first needs an address or postal code. Likewise, your internet browser needs a domainname to get you to a site.
For example, the “Facebook.com” domain name includes the name of the website (ie Facebook) and the extension of the domainname (.com). When a company (or person) buys a domainname, it can determine which server the address points to.
Domain name registrations are monitored by ICANN (Internet Corporation for Assigned Names and Numbers). ICANN maintains a central database that indicates where domainnames point to, specifying which domain extensions are available.
Not all domain names follow the same formula. For example, “.com” domains make up 46.5% of all websites, but there is still a large area for domain names like “.org” and “.net”. In general, the most common types of domains are:
TLD: Top Level Domain
As the top-level domains or top-level domains name implies, the domainname is the type of domain name at the top of the system. There are over a thousand TLDs available but the most common extensions are “.com”, “.org”, “.net”, and “.edu”.
ccTLD: County Code Top Level Domains
“ccTLD” contains international country codes and consists of only two letters, for example the extension “.us” uses for the United States. They are frequently using by companies that create private sites and make visitors feel that they have reached the right address.
gTLD: Generic Top Level Domain
A “gTLD” is a “TLD” that does not actually require a country code. Most “gTLD” is for private use, for example the “.edu” extension is for educational institutions. However, you do not have to meet any criteria to create a “gTLD” record. So the “.com” extension does not use for commercial purposes only.
Second Level Domains
You’ve probably seen these domainnames before. These are the addresses just below the top-level domain names. We won’t go into too much technical details. Because it’s easier to show by example, especially when it comes to country codes.
For example, British companies sometimes use the extension “.co.uk” instead of “.com”, which is a great example of a second-level-domain. Another second level domain is the “.gov.uk” extension, which is often used by government agencies. Finally, “.ac.uk” uses by academic institutions and universities.
What is subdomain?
Subdomains are very useful because they don’t require web developers to get extra domainnames to create sections on their sites. Instead, they can effectively point to a specific directory on the server by creating a subdomain. This is especially useful for campaign sites and different web content that needs to be separated from the home page.
Let’s explain again with an example. Facebook provides useful information for web and application developers who want to use the Facebook API via “developers.facebook.com”. Another example is “support.google.com”.