Diamagnetism is a form of magnetism that occurs in materials that do not have any unpaired electrons. When exposed to a magnetic field, these materials create an opposing magnetic field, causing them to be repelled. This phenomenon is typically very weak and is observed in substances like bismuth and copper. Unlike ferromagnetic or paramagnetic materials, which can be strongly attracted to magnets, diamagnetic materials exhibit a very subtle response. This property makes them useful in various applications, including magnetic levitation and sensitive measuring devices, showcasing the fascinating interplay between magnetism and material properties.