👉 Fluid, in its broadest sense, refers to any substance that flows freely and changes shape when subjected to an external force, encompassing liquids, gases, and plasmas. Liquids, like water or oil, maintain a definite volume but take the shape of their container, allowing them to flow smoothly without losing their cohesive properties. Gases, such as air or hydrogen, have no fixed shape and expand to fill any container they occupy, taking on the form of their surroundings. Plasmas, often referred to as the fourth state of matter, consist of ionized gases with charged particles that can flow and conduct electricity. Collectively, fluids exhibit unique behaviors like viscosity, surface tension, and compressibility, making them essential in various natural processes and industrial applications, from weather patterns to hydraulic systems.
