This document provides an overview of how internet sites are organized and linked. It explains that some sites are on the World Wide Web while others are not. Every site has a domain name, which is the part of the URL between the double slashes and first slash. Each site also has a home or main page that serves as the central page where other internal pages within the site can be accessed by clicking links. These internal links allow the user to navigate between pages within the same site domain in the URL. External links take the user to completely different domains and are identified by a changed domain name in the URL. Knowing how to identify a site's home page and internal links is important for properly citing online sources.