IEC aims to change behaviors through education within a target audience. It can occur at multiple levels - mass, community, group, family, and individual. Approaches include using various media formats, community discussions, group sessions, family discussions, and one-on-one education. Principles of effective health education include establishing credibility, engaging interest, encouraging participation, motivating behavior change, ensuring comprehension, reinforcing messages, learning through experience, building on existing knowledge, leading by example, developing good relationships, collecting feedback, and involving community leaders.