The Fourier series is a powerful mathematical tool that expresses any periodic function as a sum of simple sine and cosine waves. By combining these basic oscillations with different frequencies, amplitudes, and phases, we can reconstruct even the most complex periodic shapes. This concept reveals that any repeating signal—no matter how irregular—can be viewed as a blend of harmonically related waves. The coefficients of the Fourier series determine how much of each frequency contributes to the