Liquid is one of the fundamental states of matter, characterized by its ability to flow and take the shape of its container while maintaining a constant volume. Unlike solids, liquids do not have a fixed shape, and unlike gases, they are not easily compressible. Common examples of liquids include water, oil, and alcohol. The behavior of liquids is influenced by various factors, including temperature and pressure. Liquids can exhibit unique properties such as surface tension and viscosity, which affect how they interact with solids and gases. Understanding liquids is essential in fields like chemistry, engineering, and biology.