What Is the Concept of ‘Finality’ in Blockchain Transactions?

Finality refers to the assurance that a confirmed transaction is permanent and irreversible. In PoW chains, finality is probabilistic, meaning it's highly likely but not absolutely guaranteed.

In PoS chains with deterministic finality, a transaction is guaranteed to be irreversible after a certain protocol-defined threshold (e.g. two-thirds of validators agreeing). High finality is crucial for trust and integration with traditional finance.