Oscillating is the process of swinging or moving to and fro in a steady, uninterrupted manner, and oscillating motion is the movement created by the process. An oscillating motion typically refers to a single step of the process in one direction then again as it swings to and from the opposite direction.
Examples of oscillating motion are the swinging of a pendulum in a clock and the repetitive back-and-forth movement of a rotating fan.
Apart from the physical definition of the term, oscillating motion can also be applied to the mental process of fluctuating between ideas, opinions or convictions. Used in a sentence, this intent of the phrase is displayed when saying, "She oscillated between admiring him and being very angry with him for his actions." This implies that she is swinging back and forth between her emotions regarding the man's actions.
Oscillation is also used in the fields of mathematics and physics. In physics, it implies a repeated and regular fluctuation above and below a mean value. In mathematics, it typically refers to the differences in a function within a given interval, specifically between the least upper bound and the greatest lower bound. Another application of oscillation in mathematics is when determining the limit of the oscillating movement within an interval, also referred to as the "saltus."