Kuroobi

In East Asian martial arts, the black belt is a way to describe a graduate of a field where a practitioner's level is often marked by the color of the belt. The black belt is commonly the highest belt color used and denotes a degree of competence. It is often associated with a teaching grade though frequently not the highest grade or the "expert" of public perception. It is also a relatively recent invention (dating from the late 19th century) rather than an ancient custom.

The systematic use of belt color to denote the rank was first used in Japan by Jigoro Kano, the founder of judo, who first devised the colored belt system using obi (sash), and awarded the first black belts to denote a Dan rank in the 1880s. Previously, Japanese Koryu instructors tended to provide certificates. Initially the wide obi was used; as practitioners trained in kimono, only white and black obi were used. It was not until the early 1900s, after the introduction of the judogi, that an expanded colored belt system of awarding rank was created. Other martial arts later adopted the custom or a variation of it (e.g., using colored sashes) to denote rank. This includes martial arts that traditionally did not have a formalized rank structure. This kind of ranking is less common in arts that do not claim a far eastern origin, though it is used in the Marine Corps Martial Arts Program.

Rank and belts are not equivalent between arts, styles, or even within some organizations. In some arts, a black belt is expected in three years, while in others ten years may be common. Testing for black belt is commonly more rigorous and more centralized than for lower grades.

In contrast to the "black belt as master" stereotype, a black belt commonly indicates the wearer is competent in a style's basic technique and principles. Since in many styles a black belt takes approximately three to six years of training to achieve, a possible analogy might be a bachelor's degree: the student has a good understanding of fundamental concepts and ability, but has not yet perfected their skills. In this analogy a graduate degree would represent advancement past the first degree. Brazilian jiu-jitsu would be a notable exception to this, as a black belt for a jiu-jitsu practitioner typically takes 7-12 years of training to earn, and a black belt holder is generally viewed as an expert in the art.

...
Wikipedia