Stainless steel is an iron-based alloy composed primarily of iron, chromium, and often nickel. Its characteristic resistance to corrosion stems from the formation of a passive chromium oxide layer on its surface. This adherent, stable oxide film acts as a barrier, preventing further oxidation and resisting rust formation even when exposed to moisture or mild chemicals. Due to this inherent durability and strength-to-weight ratio, the material is widely used in applications requiring sustained structural integrity and hygienic performance, such as in industrial machinery, architectural elements, and medical devices.