Artificial ntelligence (AI) is a transformative yet double-edged technology that can advance human welfare while also posing risks to humans and society. In response, the human-centered artificial intelligence (HCAI) approach has emerged as both a design philosophy and a methodological complement to prevailing technology-centered AI paradigms. Placing humans at the core, HCAI seeks to ensure that AI systems serve, augment, and empower humans rather than harm or replace them. This chapter establishes the conceptual and methodological foundations of HCAI by tracing its evolution and recent advancements. It introduces key HCAI concepts, frameworks, guiding principles, methodologies, and practical strategies that bridge philosophical HCAI principles with operational implementation. Through an analytical review of the emerging characteristics and challenges of AI technologies, the chapter positions HCAI as a holistic paradigm for aligning AI innovation with human values, societal well-being, and sustainable progress. Finally, this chapter outlines the structure and contributions of the Handbook of Human-Centered Artificial Intelligence. The purpose of this chapter is to provide an integrated foundation that connects HCAI conceptual frameworks, principles, methodology, and practices for this handbook, thereby paving the way for the content of subsequent chapters. Ultimately, the success of AI will be measured not solely by its technical sophistication but by its enduring capacity to enhance human performance, safeguard human dignity, and strengthen societal benefits and trust.