Communication is the effective sharing or transfer of facts, opinions, or emotions between two or more people. Effective communication requires competence in listening, speaking, reading, writing, and nonverbal communication. There are various channels, methods, and classifications of communication in organizations, including downward, upward, lateral, and diagonal flows of information. Barriers to effective communication include noise, lack of feedback, improper medium selection, mental blocks, language issues, and personal, cultural, and interpersonal factors.