An electromagnetic wave is a type of transverse wave that propagates through space (and can travel through a vacuum) by oscillating electric and magnetic fields that are perpendicular to each other and to the direction of travel.

• Core idea: Electromagnetic (EM) waves are self-sustaining oscillations of electric and magnetic fields; they do not require a medium to move through.
• Spectrum: EM waves span a broad range of frequencies and wavelengths, from radio waves with long wavelengths to gamma rays with very short wavelengths. Light visible to the human eye is just a small portion of this spectrum.
• Key properties:
  • Travel at the speed of light in vacuum (approximately 3.00 × 10^8 m/s).
  • They exhibit both wave-like and particle-like behavior (photons).
  • They are characterized by frequency (or wavelength) and energy: higher frequency means higher energy per photon.

If you’d like, I can tailor a quick comparison of the main EM wave types (radio, microwave, infrared, visible, ultraviolet, X-ray, gamma-ray) focusing on typical wavelengths, energies, and common applications.