Camera Interpolation Curves

MioDioDaVinci

Teto's Territory
I've recently been getting back into MMD and have decided to make my own animations (rather than just posing characters and making photos.) But I've noticed how choppy my camera motion is. It moves from Point A to Point B with level speed throughout. Now, what I've also noticed is on motions I've downloaded (both camera and model ones) is that the little box labeled "Interpolation Curve" has hundreds of curves in it, resulting in a very, very smooth camera motion.

Would someone mind telling me what interpolations are and how they work? Perhaps you could offer a quick tutorial on how to use them? Id' greatly appreciate it.