Generative AI creates new content — text, images, code, music, video — rather than just analyzing or classifying existing data. ChatGPT generating an email, Midjourney creating an image, and GitHub Copilot writing code are all generative AI. The technology behind most generative AI is either transformer models (for text and code) or diffusion models (for images and video). Generative AI is the category that made AI mainstream because its outputs are immediately visible and useful to non-technical people.