But one thing i am still confused is, who really mine or submit these blocks?
In POS there are no miners, there are just validators. Every node that wants to be a validator has to put some ETH in stake and they cannot spend these ethers.
Now coming to who will be validating a block, the changes of a node getting a chance to add a block to blockchain depends on their ETH in the stack. The higher no of ethers in the stack, higher is the probability of getting the responsibility of adding a block.
I did a lot of search and i am clear how POW works , but in case of POS ,how a participants decides which block is honest to not get penalized if bet goes wrong .
In POS, if a validator misbehaves, the nodes verifying the block will reject the block and the ethers of the validator that he has put into stake will be slashed off. I am not sure what happens to these ETHs. So validators won't risk their coins to add an invalid tx to the blockchain. This will maintain the integrity of blockchain as in PoW.