What does 'isolate' and 'extend' mean?

[UchihaYuki]

I'm still confused after reading the doc. Please give a simple example for each.
reference: https://ngx-translate.org/reference/configuration/

Edit:
What's the relationship between translate.translations and translate.store.translations? What's the relationship between them and, 'isolate' 'and extend'?

[UchihaYuki]

It seems non-isolated translations will be put into translate.store.translations. But I still have no clue what will 'extend' do.

[UchihaYuki]

After some testing, I think 'extend' means to extend the translations in translateStore.translations.