What Is a Web Domain?
A web domain is the human-readable name used to identify a location on the internet. Instead of remembering a numerical IP address, people can enter a name such as freelancecoder.uk into a browser.
A domain is an internet name
A domain name is a name registered within the Domain Name System, or DNS.
It gives people and software a memorable way to refer to websites, servers, email services and other internet resources.
For example:
Computers and humans identify things differently
Internet systems communicate using numerical network addresses such as IP addresses.
Humans generally find names easier to remember.
DNS provides the system that connects domain names to the technical resources behind them.
DNS connects domain names to internet services
DNS stands for Domain Name System.
When someone enters a domain into a browser, DNS can be used to determine where that request should be sent.
A domain has different parts
Consider:
freelancecoder
The registered name chosen for the domain.
.uk
The top-level domain at the end of the name.
What is a TLD?
TLD stands for Top-Level Domain.
It is the final part of a domain name.
Some TLDs represent countries
Country-code top-level domains are known as ccTLDs.
| TLD | Country or territory |
|---|---|
| .uk | United Kingdom |
| .pt | Portugal |
| .fr | France |
| .de | Germany |
| .es | Spain |
A domain can have subdomains
Consider:
Here:
Other examples could include:
Different subdomains can point to different services.
What is the root or apex domain?
The domain without a subdomain is often called the apex domain or root domain.
By comparison:
contains the www subdomain.
A domain is not the same as a URL
A domain might be:
A complete URL might be:
The URL contains additional information.
| Part | Example |
|---|---|
| Protocol | https:// |
| Hostname | www.freelancecoder.uk |
| Domain | freelancecoder.uk |
| Path | /contact |
A domain is not the website itself
This is an important distinction.
You can own a domain without having a website attached to it.
You can also move a website to another hosting provider while keeping the same domain name.
Domains are registered through registrars
A domain registrar is a company authorised to register domain names for customers.
When a domain is available, you can register the right to use it for a particular registration period.
Registrars and registries are different
The registrar is normally the company through which the customer manages the registration.
The registry operates the database and infrastructure for a particular top-level domain.
Nameservers tell the internet where DNS records live
A domain is normally assigned authoritative nameservers.
These servers provide DNS information for the domain.
Changing nameservers can effectively move responsibility for managing the domain's DNS records to another provider.
DNS records control where services point
| Record | Common purpose |
|---|---|
| A | Points a name to an IPv4 address |
| AAAA | Points a name to an IPv6 address |
| CNAME | Aliases one hostname to another |
| MX | Directs email delivery |
| TXT | Stores text used for verification and policies |
| NS | Identifies authoritative nameservers |
An A record can point a domain to a server
An A record maps a hostname to an IPv4 address.
A CNAME can point one name to another
This allows the www hostname to reference another hostname instead of directly containing an IP address.
Domains can also be used for email
A domain is not limited to websites.
The same domain could also support addresses such as:
DNS records can direct email traffic to a mail provider independently of where the website is hosted.
A domain can be protected with HTTPS
HTTPS encrypts communication between a browser and a website.
HTTPS normally uses a digital certificate associated with the domain or hostname.
The domain and the SSL/TLS certificate are separate things. Registering a domain does not itself create the website, although many hosting platforms automatically provide HTTPS certificates after the domain is connected.
DNS changes may not appear everywhere immediately
DNS information is cached by resolvers and other systems.
When a record changes, some systems may continue using the older cached information until it expires.
This process is commonly described as DNS propagation.
DNS records have a TTL
TTL means Time To Live.
It tells DNS resolvers approximately how long a record may be cached before it should be refreshed.
Domain registrations must normally be renewed
A domain is generally registered for a defined period.
To continue controlling the domain, the registration normally needs to be renewed before it ultimately expires.
"Buying" a domain is really a registration right
People often say they have bought a domain.
More precisely, they have registered the right to use that domain according to the rules of the relevant registry and registrar for as long as the registration remains valid.
Domains can usually be transferred
A domain can often be moved from one registrar to another without changing the domain name itself.
The website can remain on the same hosting platform if the DNS configuration continues pointing to the same destination.
One domain can connect many services
DNS makes it possible for these services to be hosted in completely different places while sharing the same domain.
The domain and hosting can come from different companies
You do not normally have to register a domain with the same company that hosts the website.
This separation is one of the most useful features of the Domain Name System.
A simple way to think about domains
Domain
The memorable internet name.
DNS
The system that tells software where services are.
Hosting
The infrastructure that stores or runs the website.
HTTPS
The secure encrypted connection used to reach it.
A human-readable internet address.
A web domain is a registered name used to identify internet resources. DNS connects that name to websites, servers, email systems and other services. The domain, DNS, hosting and website are separate components that work together to make an internet service accessible.
