Time-based Animation
Related nodes
Generators:
LFO (Animation)
Filters:
Damper (Animation)
Oscillator (Animation)
Newton (Animation) - accelerates & decelerates
OneEuroFilter (Animation)
LinearFilter (Animation)
Tweener (Animation)
ADSR (Animation)
Decay (Animation)
DeNiro (Animation) - accelerates, drives with constant speed, decelerates (just like a taxi driver)
...and many more, see the Animation category.
When there must be a transition between a starting point (A) and a target point (B) and the animation of the value depends only on time, then the nodes from the Animation category do the tweening for you.
These nodes are building a function curve to animate from A to B and sample this curve as the time goes (independent from the framerate), returning a new value every frame.
If point B changes during the animation, the node builds a new curve and smoothly animates to the new target.
If you just want to smoothen (filter) input values, besides Damper (Value) or Newton (Value) there is also OneEuroFilter (Animation) worth checking out.
See also: