3.1 What Is a Domain Name?
The Internet connects computers, phones, servers, and other devices around the world.
For these devices to communicate, they need addresses. These addresses are called IP addresses.
An IP address is a numerical address used to identify a device or server on a network. When one device needs to send information to another device, it needs some way to know where that information should go.
Humans, however, are not very good at remembering technical addresses.
Why Domain Names Exist
Instead of typing a long IP address every time they want to visit a website, people usually type a name, such as:
google.com
wikipedia.org
michaelisuniversity.com
These are domain names.
A domain name is a human-readable name that helps people find a website, service, or online location. It gives people a simpler way to reach something on the Internet without having to remember the technical address behind it.
A simple way to think about it is that an IP address is like a building’s actual street address, while a domain name is like the name of the building.
A person might say, “Let’s meet at the library,” instead of saying the full street address every time. In a similar way, people type a domain name instead of memorizing the numerical address of a website.
However, a domain name is not the same thing as a website.
Domain Names vs. Websites vs. URLs
The domain name is the name people use to find the website. The website is the actual content, pages, images, videos, files, and features that appear after the browser connects to the correct place.
For example, in the address:
https://www.example.com/about
The domain name is:
example.com
The full address is called a URL, which stands for Uniform Resource Locator. A URL may include the protocol, the domain name, and the specific page or path being requested.
In this example:
https:// — tells the browser what protocol to use.
www.example.com — tells the browser what domain or host to contact.
/about — tells the browser which page or section to request.
People often use the words “website,” “domain,” and “URL” as if they mean the same thing. They are related, yet they are not identical.
Parts of a Domain Name
A domain name usually has multiple parts separated by dots.
Take this domain:
example.com
The .com part is called the top-level domain, or TLD. It appears at the end of the domain name. Other common top-level domains include .org, .net, .edu, .gov, and country-code endings such as .us, .uk, .ca, and .ai.
The example part is called the second-level domain. This is usually the main name chosen by the person, business, organization, or project registering the domain.
Together, example.com is a domain name.
Subdomains
Sometimes there is another part before the main domain name. For example:
www.example.com
mail.example.com
shop.example.com
The words www, mail, and shop are subdomains. A subdomain is an added section of a domain that can point to a specific part of a website or service.
For example, a company might use:
www.company.com — for its main website
store.company.com — for its online store
support.company.com — for customer support
mail.company.com — for email-related services
Subdomains help organize different services under the same main domain name.
Who Registers Domain Names?
Domain names are registered, not permanently owned in the same way a person might own a physical object. When someone gets a domain name, they usually register the right to use it for a period of time, such as one year or several years. If they keep renewing it, they can keep using it. If they forget to renew it, the domain may eventually expire and become available again.
There are several important roles in the domain name system.
- The registrant is the person, business, or organization that registers the domain name.
- The registrar is the company that sells or manages domain registrations for customers. Many people buy domains through companies such as domain registrars, website builders, or hosting companies.
- The registry is the organization responsible for managing all domain names under a particular top-level domain. For example, one registry may manage names under one domain ending, while another registry manages names under a different ending.
For a beginner, the most important idea is that a domain name is a rented name that points people toward an Internet location.
It is part address, part label, and part identity.
Why Domain Names Matter for Security
Domain names are also important for trust.
When people see a familiar domain name, they often assume they are in the right place. For example, if someone wants to log in to their bank account, they expect the domain name to match the bank’s real website. This is one reason attackers often create fake or similar-looking domain names. A malicious website might use a domain name that looks almost correct in order to trick people.
For example, an attacker might replace a letter, add an extra word, use a strange ending, or create a fake subdomain. A person who is rushing may not notice the difference.
This is why reading domain names carefully is an important security habit.
A domain name can help identify where you are online, yet it is not automatic proof that a website is safe. Anyone may be able to register a domain that looks official, professional, or trustworthy. A real-looking domain can still lead to a scam. A legitimate domain can also be compromised if attackers gain access to it.
Domain names are becoming more diverse. For many years, people mostly thought of endings like .com, .org, and .net. Today, there are many more top-level domains, including brand names, industries, cities, communities, and country-code domains. Domain names can also appear in non-Latin writing systems, making the Internet more usable for people around the world who do not primarily use the English alphabet.
This makes the Internet more flexible and more global. It also means users must learn to look carefully at the names they trust.
A domain name is one of the first things people encounter online. Before someone understands web hosting, DNS, encryption, cookies, accounts, or cybersecurity, they usually understand the basic idea of typing a name into a browser.
That simple name is connected to a much larger system.
In the next section, we will look at DNS, the system that helps translate domain names into the addresses computers use to find websites and services.