All the organisms need a well-organised system of control and coordination. Responding to stimuli is a characteristic property of all living organisms. On receiving a stimulus, the body responds in a manner that is most appropriate for its survival and functioning. The response that is given involves various organs (or parts) of body.
Thus, it is very necessary that all the organs work together in a proper coordinated way so as to provide the correct response. This working together of various organs in a systematic orderly way so as to provide proper control and response to stimulus is called coordination.