Light exhibits both particle-like and wave-like properties, leading to the understanding that it possesses a dual nature. This concept is known as wave-particle duality.
In some experiments and phenomena, light behaves like a particle, and it is described as consisting of discrete packets of energy called photons. Each photon carries a specific amount of energy and momentum, and it interacts with matter as a discrete entity. This particle aspect of light is particularly evident in phenomena such as the photoelectric effect and the emission and absorption of light by atoms.
On the other hand, light also exhibits wave-like properties. It can be described by wave equations, such as the electromagnetic wave equation, which governs the behavior of electromagnetic waves. Light waves can interfere with each other, diffract, refract, and exhibit other characteristic behaviors associated with waves.
The wave-particle duality of light is a fundamental concept in quantum mechanics. It suggests that the nature of light is inherently probabilistic, and its behavior is described by a mathematical framework called quantum electrodynamics (QED). According to QED, the behavior of light is best described by treating it as both a particle (photon) and a wave, depending on the experimental context and the phenomena under consideration.