What is defined as a sinusoidal wave with a frequency that is a multiple of the fundamental frequency?

A sinusoidal wave whose frequency is a multiple of the fundamental frequency is referred to as harmonics. In the context of waveforms, the fundamental frequency is the lowest frequency of a periodic waveform, and all other frequencies that are integral multiples of this base frequency are considered harmonics. For example, if the fundamental frequency is 100 Hz, then the first harmonic is 100 Hz, the second harmonic is 200 Hz, the third is 300 Hz, and so on. These harmonics are important in various fields such as music, acoustics, and electrical engineering, as they describe the overtones that contribute to the overall sound or signal shape.

While other terms like fundamental frequency, buffer frequency, and peak frequency may relate to certain characteristics of a signal, they do not capture the specific idea of multiple frequencies that derive directly from the fundamental frequency in the way that harmonics do. The concept of harmonics is crucial in understanding how complex waveforms are constructed and analyzed.