The Ultimate Fighting Championship is a mixed-martial-arts promotion in which a series of events, known as fight nights, take place across the world. These fights are between various styles of combat including boxing, kickboxing, and Brazilian Jiu-Jitsu. The first UFC event was held in Las Vegas on January 31, 1993. The organization was created by Art Davie and Randy Couture after they sold their successful World Wrestling Federation (WWF) to NBC for $4 billion. In professional wrestling, the name "UFC" refers to a championship that can be won only by unanimous decision by three judges. The first UFC champion was declared at the first event in Las Vegas when Royce Gracie defeated all three opponents by submission in each round. This type of championship is also called a "no-holds-barred" title because it allows for any form of physical contact during a match. The main difference between the UFC and other major professional wrestling promotions is that there are no rules against striking outside the ring in the UFC. Therefore, fighters are allowed to punch one another in the face or body with no consequences. In addition, it is legal for wrestlers to use martial arts techniques such as karate kicks and shoving matches against each other in the UFC.