Dynamic

Link Modifier  -  Dynamic alive effects that continue after the animation stop

All of theses modifiers will take the input animation in order to do some procedural animations, like Smooth , Bounce , Inertia 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 little example of their usage. Go directly in 3min to see the part over the dynamic link modifiers :