Sports betting is the activity of predicting sports results and placing a wager on the outcome. The frequency of sports bet upon varies by countries, with the vast majority of bets being placed on football, American football, basketball, baseball, hockey, track cycling, auto racing, mixed martial arts, boxing at both the amateur and professional levels and more. 

Sports betting can also extend to non-athletic events, such as reality show contests and political elections. It is not uncommon for sports betting websites to offer wagers for entertainment events such as the Grammy Awards, the Oscars, and the Emmy Awards.

Winning bets are paid when the event finishes, or if not finished, when played long enough to become official; otherwise all bets are returned. This policy can cause some confusion since there can be a difference between what the sportsbook considers official and what the sports league considers official. Customers should carefully read the sportsbook rules before placing their bets.

The betting volume at sportsbooks varies throughout the year. Bettors have more interest in certain types of sports and increase the money wagered when those sports are in season. Major sporting events that don't follow a specific schedule, like boxing, can create peaks of activity for the sportsbooks.