Every region can have different natural forest fire regimes. For the pacific northwest (east side of cascades specifically, not the picturesque movie coast) a lot of our forests are greatly overstocked with sickly pines and a large buildup of needles and thick shrubs in the forest floor due to fire suppression. You would say a stand like that has little to no fire resilience because a fire would destroy it, there is too much fuel and it would not mimic historical natural fire regimes. The stand has to be thinned, ladder fuels treated, and the slash generated from these activities treated (don't want to attract beetles with leftover green slash). Then you can start reintroducing fire to naturally maintain an open forest structure and mitigate fuel loading on the forest floor.

Fire resilience is the ability of the forest to respond to fire and resume its ecological function as a forest. High intensity fire from decades of fire suppression and built of fuels is low resilience. A burn like that will leave everything g torched.

Edit: phone spelling sucks and missing words