Grandmaster (martial arts) of "Dan" rankings and Black belt and Red belt in martial arts both derive from Judo where they were adopted by its founder Kanō Jigorō. There are many terms similar or equivalent to 'grandmaster' used by various martial arts traditions. Some of these terms derive from older systems, while others are relatively modern. Japanese martial arts commonly use Sensei (先生) meaning "teacher" or literally translated, "born first" or "one who has gone before". A "Sensei" is a person who has knowledge and is willing to teach that knowledge to another. A "Sensei" assists students in "ken shiki" "the pursuit of
Japanese martial arts ("menkyo kaiden"). In the modern system, first introduced in the martial arts through judo, students progress by promotion through a series of grades (kyū), followed by a series of degrees (dan), pursuant to formal testing procedures. Some arts use only white and black belts to distinguish between levels, while others use a progression of colored belts for kyū levels. It has often been said that forms ("kata") are the backbone of the martial arts. Nevertheless, different schools and styles put a varying amount of emphasis upon their practice. Hall, David A. "Encyclopedia of Japanese Martial Arts". Kodansha USA, 2012. Japanese