According to Wikipedia

According to Wikipedia, Self-image is a type of physically and mentally changes of human nature that portrays not just subtle elements that are conceivably accessible to target. Typically self-image or self-respect defined as the ability to believe in yourself. It will help those students especially the graduate students to know their ability to persuade themselves in every circumstances experience in every field of academic.
Beane and Lipka, (1980); Calhoun and Morse, (1977); Dickstein, (1977); Rosenberg. (1979.) “Self-image is seen as the parts of one’s mental self-portrait that are essentially expressive and nonjudgmental, while confidence is developed as those angles or dispositions that are delegated self-assess.” Some researchers define that self-image is one of the most significant in every persons to view their characteristics of how they perform their value impacts and motivate them to do their task. (e.g., Beane & Lipka, 1980; Calhoun & Mourse,1977).
For motivations behind this examination, confidence was characterized as “valuing one’s own value and importance and having the character to be responsible for oneself and to act mindfully toward others” (California State Department of Education, 1990. P, 1). It is pushes you to encourage yourself in every aspects of academic that will be the help of your success.
And somehow it will be the great achievement when you have a trust in yourself, because, most graduate students they did not achieve complete their program because of lack of confidence and belief to their self.