Communication involves the exchange of ideas through various means. It can be verbal, non-verbal, written, or oral. Effective communication in business requires a sender, medium, and receiver. It allows for the exchange of information, opinions, and understanding between parties. Communication can flow upward from lower to higher levels, downward from higher to lower, or horizontally between the same levels. Barriers to communication include perceptual differences, information overload, and complex organizational structures. The 7 C's model outlines keys to effective communication such as completeness, conciseness, clarity, and correctness.