This document discusses different levels of communication. Intrapersonal communication occurs within one's own mind and involves thoughts, feelings, and decision making. Interpersonal communication is between two people through informal conversations like talking with friends. Small group communication occurs within teams and results in group decision making and problem solving. One-to-group communication involves a speaker informing, motivating, or persuading an audience like a teacher lecturing a class. Mass communication uses media like television, radio, and print to transmit messages to a large audience without direct feedback. The document also briefly discusses barriers to communication and how to overcome them, as well as tools for effective communication.