Brazilian Jiu-Jitsu is a martial art and combat sport that teaches a smaller person how to defend himself against a larger adversary by using leverage and proper technique. The Gracie family, the founders of BJJ, modified judo and traditional Japanese jiu-jitsu to create the art.
Japanese Jiu-Jitsu was introduced to the Gracie family in Brazil around 1914 by Esai Maeda, who was a champion of Jiu-Jitsu at the Kodokan in Japan..
Gi and No Gi are the 2 forms of Brazilian Jiu-Jitsu. Gi Jiu-Jitsu is grappling with the use of a traditional Gi, which allows you to grab the clothing of your opponent. No Gi is grappling without the traditional uniform, instead you wear shorts and a rash guard.