Jiu Jitsu loosely translated means "science of softness" or "gentle art". The grappling style was intended to help unarmed soldiers to fight against armed enemies in any way possible, using the least amount of force necessary. Jiu Jitsu was the primary unarmed combat method of the Samurai.
Jiu Jitsu is said to be the ultimate self defence, armed and unarmed combat system. Many other Martial Arts are modern day descendants of Jiu Jitsu. Jiu Jitsu emphasizes turning an attacker's own force against him or herself, putting them off balance. Jiu Jitsu also emphasizes certain grappling moves and strikes to vital areas. A Jiu Jitsu student is expected to learn how to gauge the force of an opponent's attack and use it against him or her, evade attacks, use leverage against an opponent and how to attack nerves and pressure points.
The main goal in Jiu Jitsu practice is to cultivate a person's mind and body. It is not meant to be used to vent one's anger, frustration or emotional problems.