Steel and iron are both metals, but there are several key differences between them:

Composition: Steel is an alloy of iron and carbon, typically containing between 0.2% and 2% carbon. Pure iron has a much lower carbon content and is typically found in the Earth's crust as iron ore.

Hardness and strength: Steel is harder and stronger than iron due to the carbon content. The carbon in steel reacts with the iron to form iron carbide, which strengthens the material.

Temperature: Iron melts at a higher temperature than steel, requiring more heat to reach its melting point.

Applications: Steel is used in a wide range of applications due to its strength, hardness, and corrosion resistance. It is commonly used in construction, automobiles, ships, pipelines, appliances, and many other products. Iron is less commonly used in industrial applications due to its lower strength and hardness, but it is often used in the production of steel and other alloys.