How to call functions with model generated arguments

I am not a python programmer, I am a JavaScript programmer. Even though I can understand generally what they are doing, it is hard to get details.

Could someone support me on understand the difference between " How to call functions with model generated arguments" and " How to generate function arguments" on the documentation?

The first I can understand, but the second is confusing to me :unamused:

Thanks :two_hearts::ok_hand::kissing_heart: