The belt system in Jiu Jitsu represents a practitioner's skill level
https://technicalgrappling009.juniperbrief.com/posts/a-short-history-of-gracie-barra-jiu-jitsu-from-roots-to-worldwide-reach
The belt system in Jiu Jitsu stands for a practitioner's skill level, with each color suggesting progression from novice to progressed