Brazilian Jiu-Jitsu (BJJ) is a martial art and combat sport that focuses on grappling and ground fighting. It was developed in Brazil in the early 20th century by the Gracie family, who combined techniques from Judo and other Japanese martial arts to create a highly effective style of fighting.

BJJ is centered around the principle that a smaller, weaker person can successfully defend themselves against a larger, stronger opponent by using leverage and technique. The sport emphasizes ground fighting and submission holds, with the goal of controlling and submitting the opponent.

BJJ is popular among martial artists and MMA fighters, and is often used in mixed martial arts competitions. It is also used by law enforcement and military personnel as a form of self-defense training. In addition to its combat applications, BJJ is also a popular form of exercise and is known for its ability to improve physical fitness, flexibility, and mental discipline.