Fixed odds refer to a betting system where the payout is determined at the time the bet is placed. This means that the odds remain constant, regardless of any changes that may occur before the event takes place. For example, if a bettor places a wager on a sports event with fixed odds of 2 to 1, they will receive a payout based on those odds if they win, no matter what happens later. This system is commonly used in various forms of gambling, including sports betting, casino games, and lotteries. Fixed odds provide clarity for bettors, as they know exactly how much they stand to win before the event concludes.