The fundamental frequency is classified as the first harmonic, not an odd harmonic, as it serves as the baseline for counting harmonics. The discussion clarifies that the first harmonic corresponds to the fundamental frequency, while higher harmonics are integer multiples of this frequency. The concept of zero as an even or odd number is debated, but it is generally considered the zeroth harmonic. The distinction between odd and even harmonics affects the symmetry of waveforms, with odd harmonics producing symmetrical shapes and even harmonics resulting in asymmetrical ones. Ultimately, the terminology does not alter the physical properties of the waves.