Judo meaning "gentle way", is a modern Japanese martial art (gendai budō) and combat sport, that originated in Japan in the late nineteenth century. Its most prominent feature is its competitive element, where the object is to either throw one's opponent to the ground, immobilize or otherwise subdue one's opponent with a grappling maneuver, or force an opponent to submit by joint locking the elbow or by applying a choke. Strikes and thrusts (by hands and feet) - as well as weapons defenses - are a part of judo, but only in pre-arranged forms (kata) and are not allowed in judo competition or free practice (randori).
Jujutsu, means the "art or science of softness", is a Japanese martial art consisting primarily of grappling techniques. Jujutsu evolved among the samurai of feudal Japan as a method for dispatching an armed and armored opponent in situations where the use of weapons was impractical or forbidden. Due to the difficulty of dispatching an armored opponent with striking techniques, the most efficient methods for neutralizing an enemy took the form of pins, joint locks, and throws. These techniques were developed around the principle of using an attacker's energy against him, rather than directly opposing it, and came to be known as jujutsu.
There are many variations of the art which leads to a diversity of approaches. Jujutsu schools (ryū) may utilize all forms of grappling techniques to some degree (i.e. throwing, trapping, joint locking, holds, gouging, biting, disengagements, striking, and kicking). In addition to jujutsu, many schools taught the use of weapons.
Today, jujutsu is still practiced both as it was hundreds of years ago, but also in modified forms for sport practice. The Olympic sport and martial art of judo was developed from several traditional styles of jujutsu by Kano Jigoro in the late 19th century. Brazilian Jiu-Jitsu ("Jiu-Jitsu" is a common informal romanization of "jujutsu") was developed after Mitsuyo Maeda taught judo in Brazil, but at that time was still referring to it as "Kano's jujutsu".
Judo and jujutsu
Not all jujutsu was used in sporting contests, but the practical use in the samurai world ended circa 1890. Techniques like hairpulling and eye poking were and are not considered conventionally acceptable to use in sport, thus they are not included in judo competitions or randori. Judo did, however, preserve the more lethal, dangerous techniques in its kata. The kata were intended to be practiced by students of all grades, but now are mostly practiced formally as complete set-routines for performance, kata competition, and grading, rather than as individual self-defense techniques in class. However, judo retained the full set of choking and strangling techniques for its sporting form, and all manner of elbow locks. Even judo's pinning techniques have pain-generating, spine-and-rib-squeezing and smothering aspects. A submission induced by a legal pin is considered a fully legitimate way to win. Kano viewed the safe sport-fighting aspect of Judo an important part of learning how to actually control an opponent's body in a real fight. Kano always considered judo to be a form of, and a development of, jujutsu.
A judo technique starts with gripping of your opponent followed by off-balancing an opponent, fitting into the space created, and then applying the technique. In contrast, kuzushi (the art of breaking balance) is attained in jujutsu by blocking, parrying or deflecting an opponent's attack in order to create the space required to apply a throwing technique. In both systems, kuzushi is essential in order to use as little energy as possible during a fight. Jujutsu differs from judo in a number of ways. In some circumstances, jujutsuka generate kuzushi by striking one's opponent along his weak line. Other methods of generating kuzushi include grabbing, twisting, or poking areas of the body known as atemi points or pressure points (areas of the body where nerves venture close to the surface of the skin).