CSS Animations are a way to create smooth transitions and movements in web design using the Cascading Style Sheets language. They allow developers to animate changes in CSS properties over time, making elements on a webpage more dynamic and engaging. To create a CSS Animation, you define keyframes that specify the start and end points of the animation, along with any intermediate steps. This enables effects like fading, sliding, or rotating elements, enhancing the user experience without needing complex scripts or external libraries.