How are domain names structured?

Domain names are structured in a hierarchical format, consisting of several levels separated by dots (periods). The structure of a domain name typically includes the following components:

1. Subdomain (Optional): A subdomain is an optional component that appears to the left of the second-level domain. Subdomains allow website owners to create distinct sections or branches within their domain. Examples of subdomains include "www" (commonly used for the main website), "blog," "shop," or "mail."

2. Second-Level Domain (SLD): The second-level domain is the main part of the domain name, appearing immediately to the left of the top-level domain. It is the most recognizable and memorable part of the domain name and often represents the primary identity, brand, or purpose of the website. Examples of second-level domains include "google" in "google.com" or "wikipedia" in "wikipedia.org."

3. Top-Level Domain (TLD): The top-level domain is the highest level of the domain name hierarchy and appears at the end of the domain name, following the last dot. It categorizes domain names based on their purpose, type, or geographic location. Examples of top-level domains include ".com," ".org," ".net," ".edu," ".gov," and country-code top-level domains (ccTLDs) such as ".us," ".uk," ".de," and ".jp."

The structure of a domain name can be illustrated as follows:

\[ \text{Subdomain} \, (\text{Optional}) \, . \, \text{Second-Level Domain} \, . \, \text{Top-Level Domain} \]

For example, in the domain name "www.example.com":

 "www" is the subdomain (optional).
 "example" is the second-level domain.
 "com" is the top-level domain.

Domain names are used to identify and access websites on the internet, providing users with a human-readable address that corresponds to the numeric IP address of the web server hosting the website's content. The hierarchical structure of domain names helps organize and categorize websites, making it easier for users to navigate the web and find relevant information.