Harmonics are created whenever a physical system or electrical circuit vibrates, oscillates, or conducts signals at frequencies that are integer multiples of a primary base frequency. In acoustic and musical contexts, striking a string or blowing into a pipe generates standing waves that naturally produce integer-multiple overtones alongside the primary tone. In electrical power systems and audio electronics, harmonics are generated by non-linear loads—such as rectifiers, transformers, and semiconductor switching devices—which distort standard sinusoidal waveforms by superimposing higher-frequency waves onto the primary fundamental frequency.