KUMITE - THE SPIRIT OF KARATE

Kumite (組手)/ literally translated means "grappling hands" and is one of the three main sections of karate training, along with kata and kihon. Kumite is the part of karate in which a person trains against an adversary, using the techniques learned from the kihon and kata. Kumite can be used to develop a particular technique or a skill (e.g. effectively judging and adjusting one's distance from one's opponent) or it can be done in competition.
For the last point about stance and footwork: it is often taught that a karateka who wishes to be fast and agile while competing in kumite should always be 'pulsing'. Pulsing is where the karateka remains almost bouncing on the balls of their feet to maintain minimal frictional contact with the ground, allowing them to move quickly.