Internet Basics Series #1: Web addresses explained

Veronika Vilgis
  • 14 days ago
  • 3 min read

What do you type in your browser: a hostname, a domain or a website? And what’s the difference between these? In the first part of our brand new series, Internet Basics, we shed light on the structure of web addresses.

If you’re new to the web or not that familiar with how the web works and relevant language, you might just think that the web consists of websites. Obviously, it’s a bit more complex than that. In our Internet Basics series we’ll explain some of the basics and today we’re looking at what you type into your browser. Language is important and even here at where we deal with everything web-related on a daily basis, we still get confused sometimes: what’s a domain? What’s a hostname? Should I call it a website, a hostname or a domain?

So let’s look at what’s written at the top of the browser when you visit a website. The whole thing is known as a Uniform Resource Locator (URL). The URL usually starts with the protocol (http or https), then the subdomain (e.g., www or shop), then the domain followed by the top-level domain (TLD; e.g., com or de). The subdomain and domain together make up what’s called the hostname.

The structure of web addresses; Source:, September 2022


Let’s first take a look at subdomains. As a website owner you can usually choose what text to use as your subdomain. A single subdomain can be up to 255 characters long but if you use multiple subdomains (e.g.,, you’re restricted to a maximum of 63 characters.

A subdomain is often used to test a version of a website. These sites can then be used to try out new plugins or experiment with new updates before they’re published. Subdomains are also popularly used to separate mobile versions of a website (, location-specific websites ( and subsections of a website (

Another popular way to use a subdomain is to create an eCommerce business by using subdomains such as store, shop, boutique, tienda, etc. An eCommerce site often requires additional features such as the facilitation of financial transactions, so it makes sense to create these sites on different subdomains. 

The most common subdomain is www followed by variations such as ww1, ww38, etc. Among the subdomains that use complete words blog, shop, store, work and job are popular, but literally anything can be a subdomain, for example in our data we also see covid, discuss or gifts.


A domain is what you register: a unique individual name you select for your website. A domain can be just one character (e.g., but no longer than 63 (e.g., We had a closer look at which country has the longest domain length, based on character counts. Among the 51 countries included in this research, average domain length ranges from 8.2 (China) to 13.1 (Germany). The Germans are famous for creating insanely long words by just adding nouns together, so perhaps not surprisingly they also have the longest domain names on average. In contrast, a single Chinese character conveys more information than a Latin letter, perhaps explaining the shorter domain names.

Selected countries based on average character count; Source:, September 2022

Top-level domains

Top-level domains (TLDs) are the letters that you type after the domain name. Among TLDs we can further distinguish between generic TLDs, for example, com, net, org, biz, info and country-top level domains such as ik, de, nl, cl, au and more. On top of these, over the years new generic TLDs have been added like xyz, travel, community as well as geo TLDs such as london, tirol, nyc (we wrote about city and new TLDs earlier).

In our data focusing on currently active sites, we clearly see that by far the biggest TLD is .com (an abbreviation for commercial), but next we see a country top-level domain, namely .de followed by .net, .org, .uk, .cn and .ru.

Word cloud for the largest TLDs (size reflects relative frequency based on log-transformed data); Source:, September 2022

Hopefully, this post has helped you get a better understanding of the different parts that make up a web address and you now know the difference between a domain and a hostname. Certainly, if you have to make some decisions about what domain name to choose and which TLD might be right for you, here you’ve received some information about average length and what TLDs are the largest ones. The question is: do you want to stand out or fit right in? Stay tuned for upcoming posts in our Internet Basics series.