Dynamic

All of theses modifiers will take the input animation in order to do some procedural animations, like Smooth Smooth animation Read More , Bounce Create a dynamic bounce Read More , Inertia Add some inertia Read More and some others.
Their particularly is to continue to have an effect even if input values are no longer modifier.
They are particularly useful when controlling a show from a console to fluidify the transitions or animations.
Here is a small video to show you their usage. Go directly in 3min to see the part over the dynamic link modifiers :