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

To the fluctuations of the considered periodic motion of an object around a point or center. This means that the body will pass through the center point at regular intervals of time. In this type of movement the body moves forward and then backwards, relative to the Central point. While both types of movements repeated in a certain period of time.

To understand the principle of vibrational motions, one can imagine the spring that brought from the equilibrium state. If you pull the spring down, she stretched and then compressed. Such movement will occur for some time, and then the system will return to equilibrium.

To explain the oscillatory movements used by various examples. Among the most revealing you can allocate a pendulum, the steel chute with ball inside or pendulum scales. This is just a small part of models showing oscillatory motion.
For creating oscillatory movements in any system, it is removed from the equilibrium state, and then stop the exposure. When this happens, the system tends to return to its original position, but remains in this condition for a long time. This is due to the action of various forces.

However, force does not cease to operate when the system returns to its original position, and give it the excess energy. Thus, the system begins to make periodic motion or hesitate. Forces that pull the pendulum in the direction of the earth, are called gravitational forces. In turn, the forces that pull the object towards the equilibrium point, are called restoring forces. It is worth noting that such phenomena are possible only if the system is elastic.

In real life, you notice that some of the bodies that vibrate or oscillate, can produce distinctive sounds. They arise from the continuous oscillations of particles inside the bodies. All hard structures, such as bridges, vibrate when it moves transport. This movement can be accomplished in a vertical or in a horizontal plane. Therefore, in the construction of all without exception of structures is the exact calculation for the possible fluctuations.