👉 Fluid, often used in the context of fluid dynamics or in specialized engineering applications, refers to a substance that flows easily and can be manipulated to move or change its state. It is commonly found in natural processes, such as water flowing over land or air currents, and is also utilized in various industrial processes, like lubrication and cooling systems. In engineering, fluid can be engineered to have specific properties, such as viscosity or density, to optimize performance in applications ranging from hydraulic systems to chemical processing. The term "fluid" can also describe a state of matter that lacks a fixed shape but retains volume, distinguishing it from solids and gases.