This first chapter provides an overview of the development and impact of Generative AI in education, charting its journey from early AI and machine learning efforts to the current use of advanced models and tools. It offers a glimpse of the technological breakthroughs behind these recent advances and examines how these technologies are beginning to reshape educational practices through personalized learning, automated content creation, and adaptive curricula. While offering the promise of more tailored and engaging educational experiences, Generative AI introduces important ethical considerations around data privacy, bias, and the role of educators in overseeing AI use. As the first chapter of the book, it sets the stage for a deeper exploration into how Generative AI is influencing teaching and learning, balancing excitement about its potential with a cautionary awareness of its risks.