Timing and spacing in animation is very important, it makes it so the object that is being animated looks more realistic and smooth instead of having it be an unrealistic animation that looks robotic more than anything, it can help portrait the use of gravity in an animation. an example of this could be when you drop an object, every frame the object will have a bigger space than it had before since the acceleration of gravity is positive, and so that to the viewer it seems like the object is accelerating