Hard magnets, also known as permanent magnets, are materials that maintain a strong magnetic field without the need for an external power source. They are made from alloys or compounds, such as neodymium or samarium-cobalt, which have high magnetic coercivity, allowing them to resist demagnetization. These magnets are commonly used in various applications, including refrigerator magnets, speakers, and electric motors. Their ability to hold a magnetic charge makes them essential in everyday devices, providing reliable performance in both household and industrial settings.