Here is a detailed introduction:

      Chemical composition. Iron is a pure metallic element, while steel is an alloy mainly composed of iron and carbon, and may also contain other alloying elements such as cobalt and chromium.

Physical properties. Iron has relatively low strength and hardness, but it has good ductility and conductivity, while steel usually has higher strength, hardness, and wear resistance than iron. At the same time, steel has good toughness and corrosion resistance.

Application. Iron is commonly used to manufacture products that require high toughness and ductility, such as building structures, pipelines, and vehicles, while steel, due to its higher strength and hardness, is typically used to manufacture products that require higher load-bearing capacity, such as bridges, ships, aircraft, and automobiles.

In addition, there are some other differences between iron and steel, such as color and magnetism. Iron is usually light gray and has strong magnetism, while many types of steel have a darker color, and the surface may be treated to increase brightness, and the magnetism may not be obvious.