A page group is a group of pages that share something in common. This commonality must be expressed within the URL for that page. For example, Bob from bobsfruitsite.com might define a page group named Fruits, which is defined as any URL containing the string fruits.php. There might be several individual pages under this group, such as fruits.php?page=apple, fruits.php?page=orange, and so on. The Fruits page group includes all of these pages.
The page group is defined in essentially the same way as labels. You can define the page group as matching a URL exactly (one-page group), by matching a substring of a URL (e.g., "fruits.php"), or even by using a regular expression (e.g., contains "fruits.php" or "specials.php").
