Shotokan Kata

Kata is often described as a set sequence of karate moves organised into a prearranged fight against imaginary opponents. The kata consists of kicks, punches, sweeps, strikes, blocks and throws. Body movement in the various kata includes, stepping, twisting, turning, dropping to the ground and jumping.
Several Shotokan groups have introduced kata from other styles into their training but when the Japan Karate Association (JKA) was formed by Nakayama Sensei, he laid these 26 kata down as the training kata for the JKA karateka. Even today, many thousands of Shotokan Dojo only practice these 26 Kata.
Kata should be executed with the correct attitude first and foremost, if the karate practitioner has an understanding of the kata, each fast move will be executed with speed, power and intent. The karateka will execute the technique as if their life depends on it!
Kata is not a performance, or a demonstration, it is for the individual karateka to practice full techniques with 'Ikken Hisatsu' (finishing blow or to kill with one blow).
There is most definitely a health aspect to kata, the practice of kata is great for fitness, keeping the body soft, supple and agile. As the karateka gets older, a lot more emphasise is put on health and for good reason. Shotokan Resource Site