Clarity on ‘how’ the repeat functions works - performance question

Hey all,

As I’m always thinking performance first - I know how to ‘use’ a repeat but I’m wondering how it works so I can better plan uses around performance.

Does a repeat on an API response schema simply make it available again - or is it repeating the call/getting the data again?

Or is it similar to say a set value on that schema and essentially just clones what’s already been received?