...Since react-transition-group is fairly small, the overhead of including the library in your application is negligible. However, in situations where it may be useful to benefit from an external CDN when bundling. A set of components for managing component states (including mounting and unmounting) over time, specifically designed with animation in mind. The Transition component lets you describe a transition from one component state to another over time with a simple declarative API. Most commonly it's used to animate the mounting and unmounting of a component.