Yes, when it is said that "light is made of discrete particles," it refers to the concept of photons. Photons are elementary particles that are the basic units or quanta of light. They are considered both particles and waves, exhibiting properties of both.
According to quantum theory, light can be described as both a particle and a wave. The wave-particle duality of light means that light can exhibit wave-like behavior, such as interference and diffraction, as well as particle-like behavior, such as the ability to transfer discrete packets of energy.
Each photon carries a specific amount of energy, and its energy is directly proportional to its frequency. Different photons can have different electromagnetic properties, such as different wavelengths or frequencies. The wavelength of a photon determines its color within the visible light spectrum.
When many photons are present and interacting, their collective behavior gives rise to the wave-like properties of light, such as its ability to propagate, refract, reflect, and interfere. This wave nature of light can be described by mathematical equations, such as the wave equation.
So, in summary, light is composed of discrete particles called photons, each with its own specific energy and electromagnetic properties. The collective behavior of these photons gives rise to the wave-like properties of light that we observe and measure.