The payout for craps lay bets work according to true odds. The player actually bets more money than they can win in one bet. For example the 1:2 odds means that you win one unit for every two units bet (forR$10, the winning player would winR$5). These odds differ according to which numbers are bet on.
With lay betting, you are betting on any other possibility. For example, if you place a lay bet on Team A, you will make a profit if Team A loses or the game ends in a draw.