👉 A fluid is a substance that flows easily and smoothly, often in response to an applied force or pressure. It can take the shape of its container while maintaining a constant volume, unlike gases which expand to fill any space. Liquids, the most common type of fluid, exhibit properties such as viscosity (resistance to flow), surface tension (cohesion between molecules at the surface), and the ability to transmit heat and dissolve substances. Examples of fluids include water, oil, and blood, each with unique characteristics that make them essential for various biological, industrial, and everyday processes.
