What is a Second Level Domain?

Understand how a second level domain affects your business.

In simple terms, a second level domain is the name just to the left of the domain extension, the .com or .net. The website example.com was reserved for explaining the relationship between top-level domains (TLDs) and second level domains (SLDs). Here, the word “example” – directly to the left of the final dot – is the second level domain. In the website Domain.com, the word “Domain” is the SLD.

The SLD is the first point of contact internet users have with your website. It’s the most memorable part of a URL and therefore the most important. Later, we’ll get into all of the different ways you can take advantage of an SLD.

Many people are confused about the term second level domain. They don’t know where it’s located within the overall domain name, or why it matters in the first place. If you understand the full capability of a second level domain, you not only have an easier time navigating the vast expanse of the internet, but can also make your personal website more visible.

To fully understand the significance of that placement, and how to leverage second level domains in beneficial ways, it requires an understanding of the purpose of a domain name.  

Online success starts with a great domain; get yours today at Domain.com.

What is a domain name?

In the most basic sense, a website domain name is the address of a website online, just like your home address. If you want people to find your home, you give them a combination of letters and numbers that allow people to pinpoint your location. Domain names work in the exact same way. If the internet is a massive neighborhood, and websites are homes, domain names are the addresses printed on curbs or  houses.

Domain names are also unique; there are no two that are identical, on the internet. While the same address might exist for two homes that exist in two neighboring counties, the internet is basically one big, cohesive neighborhood. Because there is no duplication of domain names, each domain name is both special and valuable.

Components of a domain name

Domain names, like the one currently in the search bar of this webpage, are made up of several components. Each element of this alphanumeric string is used to help organize the web address so both computers and internet users can easily track down websites. Each web address that exists on the internet adheres to this organizational structure.

Once you understand how the structure of a domain name works, it’s  easier to understand how second level domains are important. They serve an invaluable function, are often the most memorable element of a web address, and are often highly sought after.


Everyone has heard the abbreviation “URL,” but what does it actually mean? It stands for Uniform Resource Locator, and it’s the name for the entire string of letters and symbols in a web address. In other words, each individual element of a web address is part of the overall URL.

Again, think of your street address. In its entirety it leads to your home, but it can also be broken down into parts. It includes the name of your street, your zip code, the name of your city, and the numbers that correspond to your house or your apartment. Only in its entirety can your street address lead to a precise location. Similarly, only the entire URL can lead to a web address. It is the composite of all of the individual elements that help web servers direct your computer to a website.

Transfer protocol

The transfer protocol can be found at the very beginning of a URL. In most cases, it’s represented as https://, and is also called the Hypertext Transfer Protocol Secure. This informs the website how the data from a given webpage should be transferred onto your browser.

Often, you will see websites that drop the “s” and begin with simply http://. These websites are less secure than https:// website. The “s” indicates a security layer, which encrypts the information that you enter into the website. Without that highly important little letter, it’s possible the information you input in the website can be accessed by internet users acting in bad faith.

Top level domain

In the most basic terms, a top level domain (TLD) – also called a domain name extension – is the letter combination that concludes a web address. In the hierarchy of web addresses, top level domains are the most critical.

Of all TLDs, the most famous is .com. While it’s also the most popular, there are new TLDs being invented all the time, are becoming increasingly customizable, and can be altered to fit the needs of an individual website. Some of the newest include .blog and .me.

Directories and folders

When you first click onto a website, you’ll notice that the final stretch of URL text is usually the TLD. However, if you click on a link within the website, another batch of text will often appear. This is called a directory or folder. It corresponds to specific pages within a website. If a website is like a home, directories and folders are the different rooms within it.

Second level domain example

As explained before by using “example.com” – the word “example” is a second level domain. The second level domain is important because:

  • The SLD is where you place your brand. If you’re a business, company or organization, it’s best to place your brand name within your SLD. If your desired SLD is already registered, learn   how to track down domain name owners, so you can attempt to purchase the pre-existing SLD.
  • If you set up an email address with your business website, like Gmail for Work, your SLD is the most prominent part of that address. It’s important to make sure you pick something that is both memorable and easy to type.
  • In many ways, your SLD is the identity of your website. It should correspond to the services you offer.  It distinguishes your website from others, and therefore, is worthy of careful forethought.

Reserved second level domains

The Internet Assigned Numbers Authority (IANA) reserved three domain names to be used as examples for anyone who wants to illustrate the various elements of a domain name. In all likelihood, they will never be made publicly available and will remain in their current state.

These three reserved domains are as follows:

  • example.org
  • example.net
  • example.com

Second level domain do’s and don’ts

Before you register your dream second level domain, there are a few things you should keep in mind. These quick tips can help you retain ownership of your site and make sure that you generate as much traffic as possible.

  • Remember to renew your registration. When you first register your domain, you have the option to register it for up to 10 years. It’s impossible to register it indefinitely. Make sure that you’ve secured it for the amount of time you need, and renew it when that time is up. If there is any gap between the time your ownership expires and the time you seek to renew, someone else may be able to legally acquire the domain. To avoid any issues, it’s best to set your account to auto-renew within your account management dashboard.
  • Avoid using numbers, abbreviations, or dashes in your business name. While it’s possible, they don’t make for a website name that’s easy to remember.

Use a second level domain to get your business online

Second level domains are perhaps the most important part of your domain name, so make sure you take your time when selecting one!

Online success starts with a great domain; get yours today at Domain.com.

Kristin Crabb
Kristin Crabb

Content Marketing Strategist working in the digital marketing industry. Skilled in SEO-focused content creation, keyword research and competitive analysis, interactive content, web content optimization, and landing page creation.

Kristin Crabb
Kristin Crabb

Content Marketing Strategist working in the digital marketing industry. Skilled in SEO-focused content creation, keyword research and competitive analysis, interactive content, web content optimization, and landing page creation.