LazyList keys - it helps to restore the scroll position. Apart from that, does it has any other uses? I heard using key will prevent unwanted recomposition. If yes, how does it works? what if the key has not changed but the content has been changed? And how is it different from contentType lamda?

It enables the ability to animate item positions, too. If two items switch place, for instance, they can animate to their new positions. I'm on my phone now, but I think the modifier is called

animateItemPlacement()

, and that it's defined on

LazyItemScope

or something, making it available inside of

item {}

.