Animated backgrounds are dynamic graphics or videos that move or change in some way to add visual interest or interactivity to a website, presentation, or other digital project. They can help capture attention, enhance storytelling, and create a more engaging user experience by providing movement or visual effects that bring the content to life. However, it is important to use animated backgrounds thoughtfully and considerately, as overly busy or distracting animation can detract from the main content and hinder usability.