Electromagnetic radiation refers to the energy that is propagated through space in the form of oscillating electric and magnetic fields. It encompasses a wide range of wavelengths, known as the electromagnetic spectrum, which includes radio waves, microwaves, infrared, visible light, ultraviolet, X-rays, and gamma rays.
On the other hand, waves and particles are two different ways to describe the behavior of electromagnetic radiation. According to wave theory, electromagnetic radiation exhibits wave-like properties, such as wavelength, frequency, and amplitude. These properties determine the characteristics of the radiation, such as its color (in the case of visible light) or its energy level (in the case of X-rays or gamma rays). Electromagnetic waves can propagate through a vacuum, as well as through various mediums, including air, water, or solids.
However, electromagnetic radiation also exhibits particle-like behavior, which is described by the concept of photons. Photons are discrete packets or quanta of energy that make up electromagnetic radiation. They can be thought of as particles of light, each carrying a specific amount of energy proportional to its frequency. This particle-like behavior is particularly evident when interacting with matter, as photons can be absorbed or emitted by atoms or molecules in discrete units.
In summary, electromagnetic radiation is the overall phenomenon of energy propagation through space, encompassing a range of wavelengths. Waves and particles are two complementary ways to describe the behavior of electromagnetic radiation: waves emphasize its wave-like properties, while particles (photons) describe its particle-like behavior.