Elastic, or stretchable, refers to the ability of a material to return to its original shape after being stretched or compressed. This property is commonly found in materials like rubber and certain fabrics, which can expand and then revert back when the force is removed. Elasticity is an important characteristic in various applications, from clothing to industrial products. In physics, elasticity is defined as the ratio of the change in shape or size of an object to the applied force. The concept is crucial in understanding how materials behave under stress, influencing fields such as engineering and design. Examples of elastic materials include rubber bands, spandex, and bungee cords.