Ethereum's PoS is really two consensus algorithms. The first converges rapidly but has probabilistic finality. The second has true finality, in the sense that a

Ethereum's PoS is really two consensus algorithms. The first converges rapidly but has probabilistic finality. The second has true finality, in the sense that a finalized block can't be reverted without destroying a large percentage of total stake, but it takes a while before that finality kicks in.