Brazilian Jiu-Jitsu is a martial art, combat sport and a form of self-defense that focuses on grappling and especially ground fighting. The art was derived from the Japanese martial art of Kodokan judo in the early 20th century, which was itself developed from a number of schools (or Ryu) of Japanese jujutsu in the 19th century. Brazilian Jiu-Jitsu is used extensively in mixed martial arts.
Brazilian Jiu-Jitsu was created by Helio Gracie after Helio noticed he was not strong enough to perform the Judo techniques taught to him by Mitsuyo Maeda easily which made him go on to create Brazilian Jiu-jitsu so that a person of small or weak stature like himself could defeat a much larger and more athletic person in a street fight.