What is a domain name?

What is a domain name?
A domain name is a string of text that corresponds to a numerical IP address, used to access a website from a client software. A domain name is actually the text that a user enters in a browser window to access a particular website. For example, Google's domain name is 'google.com'.

The actual address of a website is a complex numerical IP address (e.g. 103.21.244.0), but through DNS, users can enter friendly domain names and be directed to the websites they are looking for. This process is known as DNS lookup.

Who manages domain names?
Domain names are all managed by domain registries, which delegate the reservation of domain names to registration servers. Anyone who wants to create a website can register a domain name with a registration server. There are currently over 300 million registered domain names.

What is the difference between a domain name and a URL?
A URL, literally Uniform Resource Locator, sometimes called a web address, contains the domain name of a site as well as other information, including the transfer protocol and path. For example, in the URL "https://cloudflare.com/learning/", cloudflare.com is the domain name, while https is the protocol and /learning/ is the path to a specific page on the website.

What are the parts of a domain name?
Domain names are usually divided into two or three parts, each separated by a dot. When read from right to left, domain name identifiers go from the most general to the most specific. The section to the right of the last dot in a domain name is the top-level domain (TLD). This includes generic TLDs such as .com, .net and .org, as well as country-specific TLDs such as .fr and .jp.

To the left of the TLD is the second level domain (2LD). If something is to the left of the 2LD, it is called the third-level domain (3LD). Let's look at some examples:

For Google's US domain name, google.com:

'.com' is the (most general) TLD
google' is the 2LD (the most specific)
But for Google's UK domain name, google.co.uk:

'.com' is the TLD (most general)
.co'* is the 2LD
google' is the 3LD (most specific)
*In this case, the 2LD indicates the type of organisation that registered the domain (.co in the UK is for sites registered by companies)

How to secure a domain name?
Once a domain name has been registered with a registration server, the registration server is responsible for notifying the registrant when their domain is about to expire and giving them the opportunity to renew, ensuring that they do not lose their domain name. In some cases, registration servers take over their users' expired domain names by buying the domains the second they expire and then selling them back to the original registrant at an exorbitant price. It is important to choose an honest and trustworthy registration server to avoid this kind of abuse.