Kata and kumite are complementary training methods. In kata, one learns basic techniques; in kumite, one applies them with a sparring partner. The principles of kihon (see above) still apply to kumite: the karateka must apply proper karate techniques, demonstrate correct power and speed, and, above all, exercise good control -- contact is prohibited. One must remember that, while kumite is a useful application of the fundamentals learned through kata, it is not a substitute for kata.
There are three types of kumite: basic kumite, ippon (one-step) kumite, and jiyu (free) kumite.
Basic kumite, consisting of five- or three-step sparring, permits the karateka to cultivate basic blocking and attacking through prearranged techniques. It is a useful introduction to sparring for beginning students.
Ippon kumite also involves basic, prearranged techniques, but adds emphasis on body movements and proper distancing from the opponent.
In jiyu kumite, techniques are not prearranged. The karateka may freely engage her physical and mental powers, but must strictly control her attacks -- contact is prohibited. The karateka must be well-trained and disciplined enough to make a powerful blow that stops just before it reaches its target. For these reasons, only advanced students may practice jiyu kumite. (Note: Most karateka learn jiyu ippon kumite -- a combination of one-step and free sparring -- as brown belts. In this semi-free form of sparring, both sides must use basic, prearranged techniques, but may act according to their own rhythm and timing. Jiyu ippon kumite often serves as a bridge between ippon and jiyu kumite.)