A permanent bar magnet is a bar-shaped material that has a magnetic field that does not diminish or disappear over time. These magnets are made of a variety of materials, such as neodymium, samarium cobalt, or ferrite. The magnetic field is created by aligning the spins of the electrons in the material. When these spins align, they create a magnetic field that can be used for various applications, including electronics, motors, speakers, and medical equipment. Permanent bar magnets are often used in household items like refrigerators or as key parts in industrial machinery.