Brazilian Jiu-Jitsu (BJJ) is Martial Art that promotes the concept that a smaller, weaker person can successfully defend themselves against a bigger, stronger assailant by using leverage and proper technique, utilizing grappling techniques both standing and on the ground – most notably by applying joint-locks and chokeholds to control an attacker.
BJJ is recognized world-wide as one of the most effective self-defense systems ever created and is trained by military units and law enforcement agencies worldwide. It relies on proven leverage based grappling techniques, rather than size and strength; or striking techniques that can have an unpredictable results.
Aside from Self-defense, BJJ training can also be used for sport grappling tournaments (gi and no-gi) and is a major component in modern day Mixed Martial Arts (MMA). Sparring (commonly referred to as "rolling") and live drilling play a major role in training as students are able to practice their techniques against a partner who is actively defending. This practice is one of the secrets to BJJ's effectivness, as students are able improve their skills in a realistic, yet controlled, environment.