Given the ubiquity of periodic phenomena in nature, it is not surprising that oscillators play such a fundamental role in sciences and technology. In physics, oscillators are the basis for the understanding of a wide range of concepts spanning field theory and linear and nonlinear dynamics. In technology, oscillators are the source of operation in every communications system, in sensors and in radar, to name a few. As man's study of nature's laws and human-made phenomena expands, oscillators have found applications in new realms.

Oscillators and their interaction with each other, usually as phase locking, and with the environment, as manifested by a change in their operational parameters, form the basis of our understanding of a myriad phenomena in biology, chemistry, and even sociology and climatology. It is very difficult to account for every application in which the oscillator plays a role, either as an element that supports understanding or insight or an entity that allows a given application.

In all these fields, what is important is to understand how the physical parameters of the oscillator, i.e. its phase, frequency, and amplitude, are affected, either by the properties of its internal components or by interaction with the environment in which the oscillator resides. The study of oscillator noise is fundamental to understanding all phenomena in which the oscillator model is used in optimization of the performance of systems requiring an oscillator.