This document defines and discusses the key concepts of interpersonal communication (IPC), including its nature, elements, and principles. It notes that IPC occurs between people in a relationship, is influenced by both verbal and nonverbal messages, and exists on a continuum from impersonal to intimate. The document outlines the common elements of IPC like sources and receivers, encoding and decoding of messages, and the role of context. It also describes several principles of IPC, such as it being a transactional process that refers to both content and the relationship between communicators.