POS v POW

Relatively new to crypto. Got a loose understanding of the systems.

Trying to differentiate the two but I’m kinda stuck on something. I understand that mining is more energy intensive, as they’re using mining rigs to process transactions.

My confusion stems from how that differs from POS where you still end up using a computer to process transactions. There just happens to be an extra step (32ETH). Which, I guess I should ask just to be sure - are those 32 ETH just parked somewhere as collateral or is it used as part of a liquidity pool?

Of course penalties keep validators in line, but wouldn’t that imply that btc miners have the capability to misbehave in a similar manner to a bad validator (even though they have no stake)?

To me the two methods seem nearly identical. What am I missing ?

Edit: ty to everyone who’s responded so far. Learning a lot. If you can believe it, I have even more questions.

Such as: Nodes Noticed them mentioned as similar to a validator. Does running a node require a stake? Is there risk/reward to me? I don’t have the kind of capital to validate, but if running a node requires decent computing power, that I can do.