Annealing is a heat treatment process used to alter the physical and sometimes chemical properties of materials, typically metals and glass. The process involves heating the material to a specific temperature and then allowing it to cool slowly. This helps to relieve internal stresses, improve ductility, and refine the grain structure, making the material easier to work with. In the case of metals, annealing can enhance their strength and toughness, making them more suitable for various applications. For glass, the process can improve clarity and reduce brittleness. Overall, annealing is essential in manufacturing and materials science for optimizing material performance.