Fold, or bend, refers to the action of changing the shape of an object by applying pressure to it, typically along a line. This process can be seen in various materials, such as paper, fabric, or metal, where the material is manipulated to create a crease or angle. Folding is commonly used in arts and crafts, as well as in practical applications like packaging and construction. In nature, folding can also describe geological processes where layers of rock are deformed due to tectonic forces. This results in formations such as fold mountains, which are created when two tectonic plates collide and push the earth upwards, creating ridges and valleys.