How Does the Concept of “Economic Finality” Differ from “Cryptographic Finality”?

"Cryptographic finality" is the theoretical guarantee that a block is irreversible due to the cryptographic difficulty of reversing the Proof-of-Work (e.g. 6 confirmations).

It is probabilistic. "Economic finality," primarily used in PoS, is the point at which the cost of reverting a block is so high (due to slashing the attacker's stake) that it is economically irrational for any actor to attempt it.

Economic finality is a stronger, deterministic guarantee that relies on financial incentives rather than computational difficulty.