Runway Gen-2 is a multimodal AI system that can generate novel videos using text, images, or video clips as input. It offers various modes for different types of video synthesis, including text-to-video, text and image-to-video, image-to-video, stylization, storyboard, mask, render, and customization. Runway Gen-2 aims to bring the magic back to making movies by allowing users to create compelling pieces of film without actually filming anything. It is a powerful tool for video generation and can be used to enhance creativity and produce realistic outputs.