This document defines and describes communication and its key aspects. Communication is defined as the exchange of information, ideas, thoughts and feelings through speech, signals, writing or behavior between a sender and receiver. The document then outlines the main components of the communication process including the sender, message, channel and feedback. It also discusses the different types of communication such as verbal, nonverbal, and the various levels of communication like intrapersonal, interpersonal, one-to-group, and mass communication. The document concludes by covering barriers to communication and tools for effective communication.