When the body or an object moves along a closed path, such a movement called variations.However, there is a condition under which the motion should occur in the vicinity of a certain point or group of points.Fluctuations also called vibrations.

to fluctuations accepted to the periodic motion of the object around the point or center.This means that the body will pass through the center point at defined intervals.In this type of movement body moves forward and then backward, with respect to a central point.Thus both types of motion are repeated after a certain period of time.

To understand the principle of oscillating movements, it is possible to imagine a spring that was taken out of equilibrium.If the pull down spring, it will
be stretched and then compressed.Such movements will occur for some time, and then the system returns to equilibrium.

To illustrate oscillatory movements using different examples.Among the most revealing is possible to allocate a pendulum steel trough with the ball inside or pendulum weights.This is only a small part of the models showing the oscillatory motion.
to create vibrational motions in any system, it is removed from the equilibrium state, and then stop the impact.When this occurs, the system tends to return to its original position, but it does not remain in this state for a long time.This occurs because of the action of various forces.However

forces cease to operate when the system is reset, and give her excess energy.Thus, the system starts to make periodic motions or fluctuate.The forces that attract the pendulum or an object in the direction of the earth, called gravitational forces.In turn, the forces which draw the object in the direction of the equilibrium point, called restoring forces.It should be noted that such effects are possible only if the system is resilient.

In real life, you may notice that some of the bodies that vibrate or oscillate, can emit the characteristic sounds.They arise due to the continuous fluctuations of particles inside these bodies.All hard structures such as bridges, vibrate when it is moving transport.This movement can be performed in a vertical or horizontal plane.That is why during the construction of any and all constructions made an exact calculation for possible fluctuations.