A sportsbook is a gambling establishment that accepts wagers on a variety of sporting events. Unlike casinos, which are owned by local governments and operate legally under state regulations, sportsbooks are independent businesses that make money by paying winning bettors. They set their odds based on probability, and they include their commission (or “vig”) in those odds. This gives them a guaranteed profit on all bets they take.

Vigorish is a popular term for the sportsbook’s cut, but it’s actually just a part of the odds that are calculated when a bet is made. The total odds for a bet on heads or tails, for example, are 100 times the amount wagered: $100 * 100 = $10,000. This bet would win if both bettor and bookmaker accepted it, but the sportsbook still collects a $10 commission on the bet (as well as any losing bets). This is what gives the sportsbook its edge, and it’s one of the main reasons why it is difficult to beat the house long-term.

The vig is included in the odds, so bettors must understand this before placing a bet. The vig is a major source of income for a sportsbook, and it allows them to pay out winning bets and cover overhead expenses. It also keeps them afloat in an industry that can be prone to fluke results, such as a coin toss with heads or tails.

Sportsbooks offer a range of betting markets, from straight bets to parlays and futures bets. Some have a more limited offering and only accept wagers on major events. Others have diversified to include eSports and even political and cultural betting markets. Most of these sportsbooks have mobile-friendly websites and native apps for iPhones and iPads.