👉 A fluid in physics refers to a substance that takes the shape of its container but has no fixed volume, meaning it can flow and change shape under pressure or force. Liquids are characterized by their ability to flow smoothly, allowing them to fill any open space within a container. Unlike gases, which have neither a fixed volume nor shape, fluids maintain a constant density and exhibit properties such as viscosity (resistance to flow). Examples of fluids include water, oil, and air.
