Viva is an AI-powered tool for generating videos and images, offering features like text-to-image, text-to-video, and image-to-video. After logging in, you can switch between video and image tools using the toggle in the top-left corner. The prompt box at the bottom allows for both positive and negative prompts, along with adjustable settings such as aspect ratio and motion strength. Video generation times can vary based on user traffic, while the image generator typically takes about a minute per generation and produces two images per prompt.