Vibration is the rapid back-and-forth movement of physical particles as a reaction to different forces.
Vibration involves the disruption of something from its equilibrium point. This is a balanced state between opposing forces.
Vibration is usually discussed in the creation of sound.
Vibration can encompass free vibration or forced vibration.
Free Vibration
This is a type of vibration in which a force is applied to an object once and is allowed to vibrate at its frequency.
An example of free vibration is a guitar string being played.
Forced Vibration
Forced vibration is a type of vibration in which a force is repeatedly applied to an object to maintain the vibration.
The vibration of a moving vehicle is forced vibration caused by the forces from the road, springs, and engine.