Question

what is the difference between oscillation, vibration and SHM. THE atoms in a metal rod performs which type of these motions?

Answer 1

Oscillation means repeated variation about a central value, while the term vibration refers specifically to mechanical oscillations.
When an object oscillates about an equilibrium position under a restoring force, which is directly proportional to the object’s displacement is called SHM or simple harmonic motion.
The atoms in a metal rod performs vibration as a motion.

Answer: Vibration and SHM performs oscillation.
The atoms in a metal rod performs vibration.