Judo is a martial art that originated in Japan. Founded in 1882 by Dr. Jigoro Kano, Judo is derived from the martial art of Jujutsu. Dr. Kano, President of the University of Education, Tokyo, studied Jujutsu, as well as several other martial arts and took what he considered to be the best of their techniques and integrated them into what is now the modern sport of Judo. Judo is studied throughout the world, but the world headquarters for Judo is the Kodokan in Tokyo, Japan. Since there is a world headquarters, Judo is practiced essentially the same way anywhere a student may go in the world. Judo means "gentle way". This does not imply that strength is not used in Judo; instead "gentle way" means that the strength of an opponent should not be resisted. Rather, the opponents strength and force should be combined with the competitors own strength and force to be used against the opponent. This is an emphasis of one of the two maxims of Judo. The first maxim is "maximum efficiency". The second maxim of Judo is "mutual welfare and benefit". This means that when one student is practicing throwing, his partner will be practicing falling; when one is practicing holds, the other is practicing escapes.

In 1964 Judo became an Olympic sport. Judo was developed from the beginning to be a sport as well as a martial art. Dr. Kano knew that Judo would be more available to everyone if it had a sport element. The rules for the sport of Judo are relatively simple and the main parts remain mostly unchanged. Divisions are divided by sex, weight and rank and there are five main ways to win a Judo match. A competitor can throw his opponent, with control, from his feet so that the opponent lands largely on their back with force and velocity; this will score an ippon (one point) and win the match. If a throw is missing some element (control, force, velocity, or on their back), then a lesser score may be given. A match can be won by having a superior score at the end of the match time. If the competitors move from a standing position to the mat without one of them scoring an Ippon, then the competitors can engage in grappling. If a competitor can put their opponent on their back and control them for 25 seconds, this will score an Ippon and win the match. If a competitor can apply pressure to the arteries in their opponent's neck and thereby cause the opponent to submit or lose consciousness, then the competitor will win the match. If a competitor can apply pressure to the elbow joint of their opponent and cause them to submit or break the opponent's arm (a rare occurrence), the competitor will win the match.