Rust is a reddish-brown substance that forms on metal when it reacts with oxygen and moisture in the air. This process is called oxidation, and it can weaken the metal over time. Common items that can rust include iron tools, bicycles, and cars. To prevent rust, people often apply protective coatings or store metal objects in dry places. Rust can also be a sign of age and wear, giving items a vintage look. Some artists even use rust in their work to create unique textures and colors. Understanding rust helps us take better care of our belongings and appreciate the beauty in aging materials.