Liquid-phase refers to the state of matter where substances exist in a fluid form, characterized by a definite volume but no fixed shape. In this state, molecules are closely packed but can move freely, allowing liquids to flow and take the shape of their containers. Common examples of liquid-phase substances include water, oil, and alcohol. In various scientific processes, such as chemical reactions and extraction methods, the liquid-phase plays a crucial role. It allows for the mixing of different substances, facilitating interactions that can lead to new compounds or the separation of desired materials from mixtures.