Online sports betting, also known by sport booking, is the practice of placing bets on sporting events. Historically, wagers were placed on sporting events based on outcomes of the event. Despite this, PASPA has largely prevented online and in-person sports betting however Nevada has one exception. To bet, one had to visit an operator of betting. Now, booking apps have made it possible to place bets on their mobile devices and make payments. They also function as a digital clearinghouse that can receive bet calls and pay outs.