D8: How does {{ page.content }} find its template file?

I am trying to add a region to my theme (subtheme of AdaptivetTheme), and i followed the intructions, but now i don’t know how to connect the {{ page.navbar2 }} in templatesgeneratedpage.html.twig to the the file in templatesnavigationnavtwo.html.twig or if i am even supposed to be doing that…

Trying to copy an existing region as an example. The subtheme comes with a Navbar region and is listed in templatesgeneratedpage.html.twig as {{ page.navbar }} and it displays the contents of templatesnavigationmenu.html.twig (right?)

How does it know to display that file? Am I missing a key step here? (preprocessor, or some other file that defines the variables?)

If i can figure out how to make this connection, i just migth be dangerous enough to create soemthing 🙂

Thank you,

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