Vibration is the propagation of elastic waves producing deformations and tensions on a continuous medium (or equilibrium position).

In its simplest form, a vibration can be considered as a repetitive movement around an equilibrium position. The "equilibrium" position is the one it will reach when the force acting on it is zero. This type of movement does not necessarily involve internal deformations of the entire body, unlike a vibration.

It is advisable to separate the concept of vibration from that of oscillation, since the oscillations are of a much greater amplitude; For example, when walking, our legs swing, unlike when we tremble—from cold or fear. Since vibrations generate movements of smaller magnitude than oscillations around an equilibrium point, the vibratory movement can be easily linearized. In oscillations, in general, there is a conversion of kinetic energy into gravitational potential and vice versa, while in vibrations there is an exchange between kinetic energy and elastic potential energy.

Furthermore, vibrations, being periodic (or quasi-periodic) movements of higher frequency than oscillations, usually generate sound waves, which constitutes a dissipative process that consumes energy. In addition, vibrations can cause material fatigue, for example.

For small oscillation amplitudes the motion can be reasonably approximated by complex harmonic motion, with equation of motion:.

Vibration is the cause of generation of all types of waves. Any force applied to an object generates disturbance. The study of noise, vibration and harshness in a system is called NVH. These studies are aimed at measuring and modifying the parameters that give it its name and that occur in motor vehicles, in more detail, in cars and trucks.

Vibration control measures are fundamentally different from noise control measures. Although vibrations usually have similar causes and can also cause noise, they have different propagation paths. At first, sound propagates directly through air, while shocks or vibrations propagate through solid materials. The vibrations can become audible to humans if, for example, building components (ceilings, walls) emit a secondary airborne sound in the audible frequency range. Since secondary sound partially affects passive noise protection measures, such as noise barriers or soundproof windows, protection measures at the source (emission) are the most effective for these immissions (vibration, secondary sound). Measurements at the source are directed at the foundations of machines, railway tracks, etc. Measurements may include anti-vibration mats, anti-vibration pads or vibration-damping feet.[1]​ Measuring instruments and sensitive laboratory equipment, such as laboratory scales and microscopes, must also be protected from vibration to provide reliable measurement results.[2]​.