Deliquescence is the process by which a substance absorbs moisture from the air and dissolves in that moisture, forming a liquid solution. This phenomenon typically occurs in hygroscopic materials, which can attract water vapor due to their chemical properties. Common examples include certain salts, like sodium hydroxide or calcium chloride, which can become liquid when exposed to humid environments. Deliquescence is important in various fields, including chemistry and material science, as it influences the stability and handling of substances.