👉 A fluid is a substance that takes the shape of its container but not a fixed shape, flowing easily to fill any space it occupies. This characteristic distinguishes fluids from solids and gases. Examples of common fluids include water, oil, and blood. Unlike solids, which have a fixed shape and volume, and gases, which expand to fill their container, fluids can move freely and are characterized by viscosity, which is a measure of a fluid's resistance to flow.
