You should see sample programs in the Apple documentation. The navigation controller is a stack that starts at the delegation level of the application. You push view controllers onto the stack and push them when you are done ... Returning to the previous level. You can poptoroot, which drops to the lowest level just above the application delegate.
You have the opportunity to have as many navigation controllers as you have tabs in the tab bar. this is not confusing ... Apple has many good examples that illustrate them ... Believe that the pattern of Elements is one.
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