It still isn't clear to me how to verify a transaction in pos, has that been clarified? I will be nice if this is made clear or if someone points me to a thread that explains it. Thanks in advance.
in POW you perform a complex calculation (hashing) to try to find matching numbers, when its found you can claim the block has been "mined" and receives a reward with it.
in POS, you perform a complex calculation, but difficulties is much lower, while ANYONE can attempt mining in POW, POS, only people with coins in their wallet can attempt to mine when their turn is up. (coin maturity)
I dont know how Ethererum's POW would be implemented, but general logic should be similar.
Problem is.. POW benefits big hashing power owners (pools, miners with lot of rigs) POS, people with large sums of coins in their wallet wins over smaller wallet.
Neither POW, POS are perfect but each with their own benefits.