1. Chemical Composition:
• Steel: Steel is an alloy of iron and carbon, typically with a carbon content ranging from 0.2% to 2.1%. Other alloys can be added to adjust the mechanical properties of steel, such as hardness, durability, flexibility, etc.

• Stainless Steel: Stainless steel is a type of steel created by combining iron with chromium, nickel, and other alloys in addition to carbon. The chromium content enhances stainless steel's resistance to corrosion.

2. Resistance to Corrosion:
• Steel: Pure steel can rust, so steel products have a risk of rusting when exposed to oxygen.

• Stainless Steel: Stainless steel does not rust due to the passive layer created by the reaction of chromium with oxygen. This property makes stainless steel a preferred material in applications exposed to water, moisture, and various chemicals.

3. Applications:

• Steel: Steel is commonly used in construction materials, automotive components, kitchenware, and various machinery.

• Stainless Steel: Stainless steel is preferred for applications like food processing equipment, surgical instruments, tanks used in chemical processes, marine equipment, and decorative purposes. It is also widely used in applications that require high levels of hygiene.

In summary, stainless steel is different from steel due to its resistance to corrosion and high resistance to corrosion. Therefore, steel and stainless steel are used in different applications and have different chemical compositions and mechanical properties.