When you create a page, it automatically inherits the security settings and modules of its parent page. You can use this when initially creating your website for items that will be on every page, such as the All Users Security Role or the navigation module. However, should you have cause to add a page later, remember it inherits every module on the parent page in each tab, as well as the security permissions of the parent page. Also, note that inheritance only occurs when you initially create the page. Any modules or security settings added to a page do not automatically propagate down to any child pages.