As described by Jigoro Kano, the founder of judo, there are two ways of practicing judo: randori and kata.
Kata literally means “form”. It is practiced according to a pre-established system of codified exercises, while randori, which means “free practice”, is practiced freely. The goal of kata is therefore to learn the fundamentals of techniques.
Nage-no-Kata (Forms of throwing) Three representative techniques are chosen from each of five Nage-waza: Te-waza, Koshi-waza, Ashi-waza, Ma-sutemi-waza and Yoko-sutemi-waza.
Katame-no-Kata (Forms of Grappling or Holding) Five model techniques are chosen from each of three Katame-waza: Osaekomi-waza, Shime-waza and Kansetsu-waza.
Kime-no-Kata (Forms of Decisive techniques) This is to learn the techniques for serious combative fight. It consists of the techniques in a kneeling position (Idori, 8 techniques) and in a standing position (Tachiai, 12 techniques).
Kodokan-Goshin-jutsu (Forms of Kodokan Self-Defense) This consists of an “Unarmed section” and a “Weapons section”. The “Unarmed section” consists of twelve techniques while the “Weapons section” consists of nine techniques.
Ju-no-Kata (Forms of Gentleness & Flexibility) This is an expressive, gymnastic composition of the methods of attack and defense in a series of slow and moderate actions. It consists of three components, Dai-ikkyo (Set 1), Dai-nikyo (Set 2) and Dai-sankyo (Set 3), each of them has five techniques.
Based on the Kodokan nomenclature there are also:
Itsutsu-no-Kata (Forms of “Five”) These forms express the mechanism of attack and defense in an elevated way. It consists of five sequences of movements that artistically express the power of nature.
Koshiki-no-Kata (Forms of Classics) Kano Shihan highly evaluated the forms of Kito-ryu Jujutsu as they represent the essence of attack and defense. Therefore, he left the forms as Kodokan Koshiki-no-Kata, with little changes. It consists of 14 Omote (front) techniques and 7 Ura (back) techniques.