At its core, a domain name is the unique address that directs users to a specific website on the internet. It’s what users type into the browser bar to access your website, such as “example.com” or “mywebsite.org.”
Domain names simplify the process of navigating the internet by offering a memorable alternative to complex numerical IP addresses.
How Domain Names Work: Mapping Domains to IP Addresses
The internet operates on IP (Internet Protocol) addresses, which are sets of numbers like 192.168.1.1. Every website has an associated IP address, and domain names serve as human-friendly aliases that map to these IP addresses.
- Domain Name System (DNS): The DNS is a global network of servers that translates domain names into IP addresses. When a user types a domain into their browser, the DNS system checks its records and maps that domain to the correct IP address.
- Request Handling: This translation allows the user’s request to reach the right server, which then sends back the website’s content to the browser. Without this mapping, users would need to remember long IP addresses for each website (which can be hard to remember – it’s usually easier to remember “mywebsite.org” than an IP address).
Mapping Multiple Domains to a Single IP Address
Oftentimes a website will use a unique IP address, where it’s the only website on that IP address. However, there are many cases where a website will share the same IP address as other websites. This happens in shared hosting environments, where multiple domains are hosted on the same server to optimize resource usage and reduce costs. In these setups, a single IP address serves multiple websites, distinguishing them by their unique domain names rather than by unique IPs.
It can also happen on Content Delivery Networks (CDNs), where the network will cache a copy of multiple websites for faster delivery to end users.
Here’s how this works:
- Shared Hosting: In shared hosting, a single server with one IP address hosts many websites. The server uses a technique called Server Name Indication (SNI), part of the TLS protocol, to identify which website to serve based on the domain name requested by the browser. When a user enters a specific domain name, the server checks the domain in the request header and returns the appropriate website files.
- Content Delivery Networks (CDNs): CDNs often use shared IP addresses to cache copies of websites in various locations worldwide. Many websites may share a CDN IP because it’s used to speed up access to the site rather than directly hosting it.
- Virtual Hosts: On web servers like Apache or Nginx, administrators can configure virtual hosts to associate multiple domain names with the same IP. This allows each domain to serve its unique content while pointing to the same IP address.
This sharing is transparent to the end user, who interacts only with the domain name itself. However, in some cases—such as needing SSL certificates in older systems—dedicated IP addresses might still be preferred or required.
In summary, not every website needs a unique IP address, especially in modern shared hosting or CDN-based setups. But each website still requires a unique domain name to differentiate itself within shared hosting environments.
Structure of a Domain Name: Top-Level, Second-Level, and Subdomains
Domain names are structured in levels, primarily divided into two key parts (or three if you use a subdomain):
- Top-Level Domain (TLD): The TLD is the extension at the end of the domain name, such as
.com,.org, or.net. TLDs are managed by organizations like the Internet Assigned Numbers Authority (IANA), which oversees the global TLD list. Some TLDs are restricted for specific uses (e.g.,.govfor U.S. government websites). - Second-Level Domain (SLD): This is the main part of the domain name, which is unique to your website (e.g., “example” in
example.com). The SLD is combined with the TLD to create a full domain name, forming the main address users recognize. - Subdomains (Optional): Subdomains are additional divisions within a primary domain. For instance, “blog.example.com” is a subdomain of “example.com” and can be used to organize different sections of a website.
Common TLDs
The following top-level domains are the most common TLDs that many people think of when they think about a domain name:
- .com: Commercial
- .org: Non-profit organizations
- .net: Network organizations
- .edu: Educational institutions (restricted)
- .gov: U.S. government (restricted)
- .mil: Military (restricted)
However, this is just a fraction of the number of TLDs available these days.
Full List of TLDs
In the early days of the web, the number of TLDs available were not much more than the ones listed above. Since then, more TLDs have become available, and there are now a vast ocean of opportunities if you’re looking to register your own domain name.
For a complete list of all TLDs, including country-specific ones like .uk or .ca, check IANA’s official list.
How to Choose the Right Domain Name
Choosing a domain name is an important step in branding your online presence. Here are some tips:
- Keep it Simple and Memorable: Short, easy-to-pronounce names are more likely to be remembered.
- Use Keywords Wisely: For SEO purposes, it can help to include relevant keywords, but avoid keyword stuffing.
- Avoid Hyphens and Numbers: These can be confusing and hard to remember.
- Pick the Right TLD:
.comis the most widely recognized, but other TLDs like.orgor country-specific TLDs might suit your site’s purpose better.
How to Register a Domain Name
To register a domain name, you’ll need to go through a domain registrar (like ZappyHost). Here’s what the registration process involves:
- Availability Check: Use the registrar’s search tool (such as ZappyHost’s domain search) to see if your desired domain is available.
- Choose Registration Period: Domains are usually registered on a yearly basis, with options to prepay for multiple years.
- Provide Contact Information: As part of ICANN regulations, you’ll need to provide contact information for the domain registration, though some registrars offer privacy protection options.
- Payment: Pay the registration fee. Costs vary based on TLD and registrar.
Once confirmed, you should be able to see the domain listed in your account at your registrar. You can now go ahead and use the domain for its intended purpose.
Domain Renewal
It’s important to understand that registering a domain doesn’t mean owning it indefinitely; it simply reserves the domain under your name for the duration of the registration period.
So if you want to keep the domain name for longer than the registration period, you’ll need to renew it before it expires. If you don’t do this, it will expire and become available for others to register.
Most registrars offer an auto-renewal option, whereby they automatically charge your card that’s stored on file just prior to the domain’s expiration date. A good registrar will notify you prior to this, and also let you know if there are any issues with renewing it (for example, if your credit card has expired). In any case, if the domain name is important to you, you should keep a very close eye on things, and do everything you can to prevent the domain from expiring (and being made available to everyone else).
Mapping a Domain to a Website
To make a domain name functional, it needs to be mapped to a hosting server where the website files are stored. Here are the high-level steps involved in doing that:
- Access Your Domain’s DNS Settings: In your registrar’s control panel, you’ll find DNS settings where you can specify nameservers provided by your web hosting provider.
- Add DNS Records: Typically, you’ll add an A record pointing to your website’s IP address, and perhaps some other records, such as an MX record for your email and a CNAME record for each subdomain (such as a
wwwsubdomain). It’s possible that your web host has already added these records for you, and so simply changing the nameservers (i.e. previous step) could be all you need to do. - Propagation Time: DNS changes can take anywhere from a few minutes, to a few days to fully propagate across the internet. During this period, it’s possible that some users will see your website and others won’t. That said, there are some methods that can be used to speed up propagation.
Why Mapping is Necessary
Mapping your domain name to an IP address ensures that users are directed to the correct server that hosts your website. Without this connection, the domain would not lead to any website.
Most domain registrars incorporate a “parked domain” page for domains that haven’t been mapped, and so if you haven’t yet mapped your domain to a website, you’ll probably see such a page.
Additional Domain Options
While the most common purpose of registering a domain name is to provide the base URL for a website, there are some additional options available to us.
Domain Forwarding
Domain forwarding is the process of redirecting one domain to another URL. For example, if you have both example.com and example.net, you could forward example.net to example.com so that visitors end up at the same website regardless of which address they enter.
There are two main types of redirection:
- 301 Redirect (Permanent): Used for permanently redirecting one domain to another.
- 302 Redirect (Temporary): Used when the redirect is temporary.
Your domain registrar may also provide some other options, such as cloaking and masking. Some of these additional options should be used with caution, as you may find that they cause issues with search engines and for usability.
Subdomains
A subdomain is a separate part of the domain, that appears before the second-level domain. For instance:
shop.example.comfor a store sectionblog.example.comfor a blog
Subdomains allow you to create separate sections within your website, each mapping to a different subdomain. For example, a blog could have the following pages:
blog.example.com/what-is-a-domain-nameblog.example.com/how-to-register-a-domain
It’s also true that a blog could use the following format:
example.com/blog/what-is-a-domain-nameexample.com/blog/how-to-register-a-domain
However this format doesn’t use a subdomain. The subdomain comes to the left of the second-level domain (which in this case is example).
Subdomains can be useful for organizing large websites or creating specific areas of functionality within a domain.
Email Aliases
While having a domain name enables you to host your own email address, some registrars also offer email aliasing. Email aliasing allows you to create branded email addresses like [email protected] that forward to your personal email.