What is frequency variation?

Frequency variation refers to the changes in the frequency of a signal or waveform over time. This can occur in various contexts, such as in audio signals where pitch may fluctuate, or in telecommunications where signal frequencies can shift due to environmental factors or equipment instability. In a broader sense, frequency variation can also apply to any periodic phenomenon, indicating how the intervals or rates of occurrence can differ from a standard or expected value. Such variations can affect the quality and clarity of signals in various applications.