The document discusses the concept, process, functions, principles, importance, and reference of communication. Communication is defined as the exchange of ideas, feelings, and emotions between two or more people to create mutual understanding. The communication process involves a sender sending a message through a channel to a receiver. Effective communication principles include clarity, completeness, conciseness, courtesy, correctness, and coordination. Communication is important as it brings people closer, saves time, breaks barriers, and results in common understanding.