Electromagnetic radiation consists of sinusoidal electric and magnetic fields, with intensity defined as Power Flux Density (PFD) in watts per square meter (W/m2). The relationship between the RMS amplitudes of these fields and PFD is established through the intrinsic impedance of the medium, which is 377 Ohms for free space. For peak amplitudes, the PFD is halved compared to RMS values. The equations PFD = E^2 / R and PFD = R H^2 illustrate the connection between electric field (E), magnetic field (H), and intensity. Understanding these relationships is crucial for analyzing electromagnetic radiation properties.