Self-system is the concept of the possible self represent individuals’ idea of what they might become, what they would like to become and what they are afraid of becoming.
Self image/future self image is perceived as plausible and is in harmony ̶ or least does not clash ̶ with the expectation of the learner’s family, peers and other elements of the social environment.
Self-concept is to be yourself; what you are, what you think.
Self-discrepancy is postulation that motivation involves the desire for people reduce the discrepancy between their actual and idea/ought selves.