Boxing, nicknamed the "sport of kings" and also called pugilism or prizefighting (when referring to professional boxing), is a sport where two participants of similar weight attack each other with their fists in a series of one to three-minute intervals called "rounds". In both Olympic and professional divisions, the combatants (calledboxers or fighters) avoid their opponent's punches whilst 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 ofrounds 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 a TKO is a knockout or KO. You will see on boxers' records the mention only of "KO". The phrase "technical knockout" usually only appears in contemporaneous news articles.
Professional bouts are far longer than Olympic bouts (ranging from four to twelve rounds), headgear is not permitted, and boxers are generally allowed to take much more punishment before a fight is halted. At any time, however, the referee may stop the contest if he believes that one participant can not intelligently defend him or herself due to injury.