Boxing, also called prizefighting (when referring to professional boxing), the sweet science (a common nickname among fans) or the gentleman's sport (used mainly in England), is a sport and martial art in which two participants of similar weight classification fight each other with their fists in a series of one to three-minute intervals called "rounds". In both Olympic and professional divisions, the combatants (called boxers or fighters) avoid their opponent's punches while trying to land punches of their own. Points are awarded for clean, solid blows to the legal area on the front of the opponent's body above the waistline, with hits to the head and torso being especially valuable. The fighter with the most points after the scheduled number of rounds is declared the winner. Victory may also be achieved if the opponent is knocked down and unable to get up before the referee counts to ten (a Knockout, or KO) or if the opponent is deemed too injured to continue (a Technical Knockout, or TKO). For record-keeping purposes, a TKO is usually counted as a knockout when calculating the total knockouts. A TKO can occur at any time. Source: Wikipedia