Explanation: Complex waveforms can be decomposed into a sum of simple sine waves at a fundamental frequency and its integer multiples, known as harmonics, through a process called Fourier analysis. A **sawtooth wave** is unique in that its Fourier series includes the fundamental frequency and *all* integer harmonics (1st, 2nd, 3rd, 4th, and so on). The amplitudes of these harmonics decrease inversely with their harmonic number. In contrast: * A **square wave** consists of the fundamental frequency and *only the odd* harmonics (1st, 3rd, 5th, etc.). * A pure **sine wave** or **cosine wave** is a single-frequency waveform and does not contain any harmonics. They are the basic building blocks of more complex waves.