Self-efficacy, defined by psychologist Albert Bandura, is an individual's belief in their capacity to execute behaviors necessary to produce specific performance attainments. It shapes how people think, behave, and feel, influencing everything from motivation and goal-setting to resilience in the face of failure. Unlike global self-esteem, self-efficacy is domain-specific and malleable, making it a powerful lever for personal and professional growth. Understanding how to systematically build self-efficacy—through mastery experiences, social modeling, persuasion, and physiological state management—provides a practical roadmap for developing confidence that translates directly into improved performance.