👉 A fluid is a substance that takes the shape of its container while maintaining a constant volume, unlike gases which expand to fill any space and liquids which maintain a fixed volume but can change shape. Fluids exhibit viscosity, which is a measure of their resistance to flow, allowing them to move smoothly and continuously. They also have surface tension, a property that enables them to resist external forces and form droplets or maintain a thin layer on surfaces. Fluids can be liquids, gases, or colloids, each with unique properties that influence their behavior in various contexts, from the flow of blood in the human body to the movement of water in pipes.
