Both aluminium and brass are metals, but they differ in properties and uses: Composition: Brass is an alloy primarily made of copper and zinc, while aluminium is a pure elemental metal. Weight: Aluminium is lighter than brass. Colour: Aluminium has a silvery-white appearance, while brass has a golden-yellow hue. Corrosion: Aluminium forms a protective oxide layer making it more resistant to corrosion, while brass can tarnish or corrode, especially in the presence of certain chemicals or moisture.