Flux refers to the flow or movement of a substance, energy, or information from one place to another. In physics, it often describes how much of a quantity passes through a surface over time, such as the flow of electricity or heat. The concept is essential in various fields, including thermodynamics, electromagnetism, and fluid dynamics. In a broader context, flux can also indicate change or variability in a system. For example, in ecology, the flux of nutrients in an ecosystem can affect the health of organisms. Understanding flux helps scientists and engineers analyze and predict behaviors in complex systems, such as climate change or chemical reactions.