concept of needs and drives need, "need is a certain lack within an organism.an animal that needs something is simply means it lacks some thing." drive, " a drive is an aroused state resulting from some bodily or tissue need,such as need for food,water and oxygen."
motivation definition " motivation is the general term for all the processes involved in starting ,directing and maintaining physical and psychological activities."(zimbardo and gerrig 1996) "a motive is an internal activator or modifier"(dr.munn)