Creating a Plugin confusion with examples in Codex

I’m reading through the Codex to learn how to properly make a plug-in and I’m stuck on what the difference is between the examples on Adding Administration Menus sample options page and the Creating Options Pages example options page (barring the fact that this example still uses deprecated functions…come on WordPress!!)

They both create options pages, correct? Then why are they so vastly different from one another? Am I missing something?