Communication involves sharing ideas, thoughts, and feelings between people so they can be understood. It can be both verbal through speaking and writing, and nonverbal through body language and signals. There are various barriers that can interfere with effective communication, such as lack of clarity, noisy environments, differences in perception, and cultural differences. Formal communication in organizations follows defined downward and upward channels from superiors to subordinates. Informal communication spreads rapidly through the grapevine network in any direction without set channels.