Lightweight materials are substances that have a low density, making them easier to handle and transport. These materials are often used in various industries, including automotive and aerospace, to improve fuel efficiency and reduce overall weight. Common examples include aluminum, carbon fiber, and plastic composites. The use of lightweight materials can enhance performance and durability while minimizing energy consumption. For instance, aircraft made with these materials can achieve better fuel economy, while bicycles designed with lightweight components can offer improved speed and maneuverability.