👉 A fluid, in the context of physics and materials science, is a substance that flows easily and can change shape to fill any container or mold. Liquids are characterized by their viscosity, which is a measure of their resistance to flow; they can move from areas of higher concentration to lower concentration. Examples of fluids include water, oil, and blood. Unlike solids, which maintain a fixed shape, fluids adapt to their surroundings and can take the form of any container they are poured into. This unique property makes fluids essential in various natural processes and technological applications, from the movement of ocean currents to the functioning of engines and hydraulic systems.
