Corrosion is the gradual destruction or deterioration of materials, usually metals, due to chemical reactions with their environment. It typically occurs when metals react with moisture, oxygen, acids, or salts, leading to the formation of oxides or other compounds. This process can weaken structures and components, making corrosion a significant concern in industries like construction, automotive, and manufacturing. Preventive measures include coatings, cathodic protection, and material selection to enhance durability.