Kumite, or sparring (lit. Meeting of hands), is the practical application of kata to real opponents. While the techniques used in sparring are only slightly different than kihon, the formalities of kumite in Shotokan karate were first instituted by Masatoshi Nakayama wherein basic, intermediate, and advanced sparring techniques and rules were formalized.

Source: http://en.wikipedia.org/wiki/Shotokan#Kihon