自信 (zìxìn) literally combines 自 (zì), meaning 'self' or 'oneself', and 信 (xìn), meaning 'to believe' or 'trust'. Together, they form a compound that expresses the psychological state of trusting one’s own abilities, judgment, or worth. It functions both as a noun ('self-confidence') and as an adjective ('confident'), often describing a person’s demeanor, attitude, or inner strength.

This word is commonly used in educational, professional, and personal development contexts — for example, when encouraging students to speak up in class, advising job seekers before interviews, or reflecting on emotional growth. Unlike the more formal or literary term 自尊 (zìzūn, 'self-respect'), 自信 emphasizes active belief in one’s capacity rather than inherent dignity. It carries a positive, empowering connotation and appears frequently in motivational speech, psychology discussions, and everyday encouragement.