If you submitted a bid into an auction epoch, you will need to reveal your bid to win the epoch. I.e. if you forget to reveal your bid but your bid was the highest bid, you will not win the auction epoch.
During the reveal period, you will not be able to submit a new bid. By the end of the reveal period, if you do not have the highest bid, whether you chose to reveal or not, you will get your bid amount returned.
If you have the highest bid by the end of the reveal period, you will become the winner and receive exclusive right to fill the underlying orders of the epoch. Note this is a right and if you choose to not fill, you will not be refunded the bid amount.