This chapter introduces the foundational concepts of ethics and explores their relevance for software development. It distinguishes between descriptive, normative, and meta-ethics and offers an overview of key ethical theories, including deontology, consequentialism, virtue ethics, and contractualism. Rather than prescribing a single moral framework, the chapter embraces ethical pluralism, emphasizing the importance of deliberative judgment and context-sensitive reasoning in addressing moral challenges in software engineering. The chapter further examines the role of values, virtues, and attitudes, arguing that ethical reflection must extend beyond rules or outcomes to encompass the character and intentions of developers and organizations. It critiques common misconceptions—such as moral relativism, solutionism, and technical determinism—and frames ethics as a proactive, practice-oriented endeavor. Building on this foundation, the chapter outlines the distinction between applied and domain-specific ethics, demonstrating why software ethics must be understood as its own normative field shaped by the specific characteristics of digital technologies.