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Animation can enhance an application's interactive feel. It can make for smoother transitions when items appear and disappear. Of course, you should use animation with taste and restraint—if you animate everything in your application, it will be a bewildering mess. You should also take care not to frustrate your users by forcing them to wait for animations to finish before proceeding. Fortunately, WPF keeps all user interface elements active while animations are in progress.
All animations are described by timelines, which are objects that describe what happens over some particular stretch of time. Timelines form a hierarchy, allowing the relationships between different parts of an animation to be expressed. The execution of animations is controlled by "clocks," which provide us with a means of starting and stopping animations. You can add animations to the triggers section of any element, and to styles and templates. The animation's timing system can synchronize with media playback, enabling animations to coincide with events in audio or video sources.