Noble metals are a group of metals that are resistant to corrosion and oxidation in moist air. This group primarily includes gold, silver, platinum, and palladium. Their unique properties make them highly valuable for various applications, including jewelry, electronics, and catalytic converters. These metals are often used in investment and as a hedge against inflation due to their rarity and intrinsic value. The term 'noble' reflects their resistance to chemical reactions, which sets them apart from more reactive metals. Their beauty and durability also contribute to their desirability in decorative arts and high-end products.