Today Internet plays a very important role in services of Health Care. If you are a medical practitioner or any health care worker, you should be well verged of Internet browsing. In the context of the internet, a domain or a domain name is essentially the address of a website. It’s what you type into the address bar of your web browser when you want to visit a site. For example, in the URL, is the domain name.

Top-Level Domains (TLDs)

Top-Level Domains (TLDs) are the highest level of domain names in the root zone of the internet’s domain name system (DNS). They appear at the end of a domain name, such as .com, .org, .net, etc. There are over a thousand TLDs available but we’ll focus on the most common ones:

  1. .com: Short for commercial, .com is the most widely used TLD. It is used by businesses, blogs, and many other types of websites.
  2. .org: This stands for organization. It is commonly used by non-profits and trade associations.
  3. .net: Short for network, .net was originally intended for internet service providers or networks of computers, but now it is a general-purpose namespace.
  4. .gov: This is used by government entities in the United States.
  5. .edu: This is used by educational institutions like colleges and universities.
  6. .mil: This is used by the U.S. military.

Country Code Top-Level Domains (ccTLDs)

Country Code Top-Level Domains (ccTLDs) are two-letter TLDs reserved for specific countries or territories. For example, .uk for the United Kingdom, .au for Australia, .jp for Japan, and .in for India.

Second-Level Domains

Second-Level Domains are directly below TLDs and are often the name that a company or individual has registered. For example, in, example is the second-level domain.


A subdomain is a domain that is part of a larger domain. It’s the third level domain of a domain name. For example, in, blog is the subdomain.

 Hence Domains are a fundamental part of how the internet works, providing a human-friendly way to navigate the web. Understanding the structure and purpose of different types of domains can help us better understand the internet’s architecture and how it keeps our online world organized and accessible.