Taxonomy is the word used to describe the structure of a website and how pages are organized. You probably have categories and subcategories of pages, also known as parent and child pages. When you create a child page, the URL will also take on the name of the parent page. A common example is a services page being the parent page and then each actual service would have a child page. You end up with something like www.example.com/services (parent) and www.example.com/services/auto-repair (child). Not only is this more user friendly, but this also helps Google and other search engines easily crawl your site and will help with SEO.