This document discusses the universal elements of communication and different types of communication channels. It outlines two features of communication: universal elements present in all human communication and basic facts about the nature of communication. These include communication environment, use of symbols, mental filters, imperfect communication, meaning depends on context, personality influences communication, and empathy. The document also discusses formal and informal communication channels, their advantages and disadvantages. Formal channels include reports and instructions, while informal or "grapevine" channels spread rumors quickly between employees.