Insulators are materials that resist the flow of electric current or heat. They are commonly used in electrical applications to prevent unwanted energy transfer, ensuring safety and efficiency. Examples of insulators include rubber, glass, and certain plastics, which help protect wires and components from electrical shock. In thermal applications, insulators help maintain temperature by reducing heat loss or gain. Materials like fiberglass, foam, and wool are often used in buildings to keep homes warm in winter and cool in summer. By minimizing energy transfer, insulators contribute to energy efficiency and comfort in various environments.