Photons are elementary particles that represent the quantum of light and all other forms of electromagnetic radiation. They are massless and travel at the speed of light in a vacuum, making them fundamental to our understanding of the universe. Photons exhibit both wave-like and particle-like properties, a phenomenon known as wave-particle duality, which is central to quantum mechanics. In practical terms, photons are responsible for the transmission of light and energy. They play a crucial role in various technologies, including lasers, solar panels, and fiber optics. Understanding photons helps scientists explore the nature of light and its interactions with matter, leading to advancements in fields like telecommunications and medicine.