A bookmaker is a person or company who takes bets on sports, horse racing, and other events. They set odds that determine how much a person will win or lose if their bet is correct. For example, if you bet on the New England Patriots in a football game, the bookmaker might offer odds of 2-1. That means if you bet $1 and the Patriots win, you will get back $2. If they lose, you lose the dollar you bet. The bookmaker makes money by taking a percentage of all the bets they take.