This chapter introduces the evolving role of artificial intelligence (AI) and machine learning (ML) in public health, with a special emphasis on the growing importance of generative AI (GenAI) tools such as ChatGPT. These tools are increasingly applied to tasks such as programming support, data analysis, and facilitating learning. A central theme of the chapter is the importance of acquiring solid R programming skills, which provide the foundation for both responsible use and critical evaluation of AI-driven outputs. The discussion highlights not only the opportunities created by GenAI—such as efficiency and accessibility—but also the challenges, including accuracy, transparency, interpretability, and potential bias. The chapter further outlines the book’s goals: building technical skills, applying ML to pressing health problems, and cultivating ethical awareness in AI-assisted research and practice.