Loading php files

Hello everybody,

In the theme I currently have I have a lot of strange pages like shorts.php or bottomblock.php .

I also have a photos.php made myself.

But I really dont understand HOW and WHERE these pages are being called to load and where they need to be loaded.

In the index.php I only see: get_header or get_footer for an example.

But where are those individual pages parts being called up because I cant seem to find it and I want to add a piece to the page.

Thanks,

Cyril