Vibration
A common thing everyone observe in their daily life
Vibration, a periodic back-and-forth motion of a rigid or elastic body from its position or equilibrium condition. This to and fro motion can be random, like a moving pendulum or periodic, such as a fired bullet.
Categories

Free Vibration
Vibrations that usually occurs as sinusoidal. To get it in simpler way; when we gave an initial input to a mechanical object or medium to make it in a motion or swing and let it to vibrate freely.

Forced vibrations
When a mechanical system driven by repeated external disturbances or forces. These disturbances can be random or periodic (harmonic or non-harmonic).

Damping Vibrations
All systems or movements are subjected to frictional forces, and these forces make system energy dissipated which results in continuously and steadily reduce the amplitude of a vibrating system, such forces are known as damping forces. These forces help system to bring back to its equilibrium state.
Free vibrations
Doorbell
We press the button once and it continuously vibrates for a particular time period
Swing
Just pull it back and let it move to and fro freely
Forced vibrations
Earthquake
Buildings start vibrating because of external forces
Uneven Roads
Vehicles passing through rough pathways have vibrations due to external forces
Damping Vibrations
Bridge suspensions
Reducing the impact of load or traffic
Vibration pads
Absorbs most of the vibration or forces created by equipment