This chapter discusses 5 main points about effective on-the-job communication: 1) Writing is an action that exerts power to achieve results, 2) Technical documents must be usable and persuasive, 3) Meaning arises from dynamic interactions between readers and texts, 4) Technical writing is reader-centered, and 5) Writing has ethical dimensions. The document explores these concepts in more depth, discussing how language shapes thinking, how writing acts on people, the importance of persuasion and usability, and what reader-centered writing means for producing documents.