BJJ stands for Brazilian Jiu-Jitsu. It is a martial art and combat sport that focuses on grappling and ground fighting techniques.

Developed from traditional Jiu-Jitsu practices in Brazil, BJJ emphasizes leverage and technique to allow a smaller or weaker person to defend themselves against a larger opponent. Practitioners, known as "jiu-jiteiros" or "jiu-jitsu practitioners," use a variety of techniques including joint locks, chokes, and positional control to submit their opponents.

BJJ has gained popularity worldwide and is commonly practiced both recreationally and competitively.