Judo is many things to different people. It is a fun sport, an art, a discipline, a recreational or social activity, a fitness program, a means of self-defense or combat, and a way of life. It is all of these and more.
Kodokan Judo comes to us from the fighting system of feudal Japan. Founded in 1882 by Dr. Jigoro Kano, Judo is a refinement of the ancient martial art of Jujutsu. Dr. Kano, President of the University of Education, Tokyo, studied these ancient forms and integrated what he considered to be the best of their techniques into what is now the modern sport of Judo.
Judo was introduced into the Olympic Games in 1964 and is practiced by millions of people throughout the world today. People practice Judo to excel in competition, to stay in shape, to develop self-confidence, and for many other reasons. But most of all, people do Judo just for the fun of it.
The belt and ranking system of Judo is similar to that of Brazilian Jiu-Jitsu. This is for very good reason as Brazilian Jiu-Jitsu had spawned from Judo in the early twentieth century when Judo expert Mitsuyo Maeda moved to Brazil. He would teach the Gracie family Judo, which would turn into Brazilian Jiu-Jitsu. For that reason, the ranking system in both Judo and Brazilian Jiu-Jitsu are very similar to each other.