The simplest of the three types, the permanent magnet, is made by magnetizing a special material using an external magnetic field. Once the external field is removed, the permanent magnet will retain some degree of magnetism and behave like a magnet for a long time. Metal alloys such as Neodymium-Iron-Boron (NIB) or Aluminum-Nickel-Cobalt (Alnico), are often magnetized as powders, resins, or bulk materials that are then formed into shapes you see on your refrigerator at home like horseshoes, donuts and circles.

Electromagnets are made by winding a coil of wire around a piece of material called the core. The core of many electromagnets is made of iron. When a voltage is applied across the wire, electric current will flow through the coil and create a magnetic field in the vicinity of the coiled wire. It is interesting to note that the strength of the magnet will change depending on the amount of electricity flowing through the coil (the more current that flows, the stronger the magnet), and the north and south poles of the magnet can be switched by reversing the direction of the current flow.

The third type of magnet to consider is a relatively new type that has developed over the last 30 to 40 years with the discovery of superconducting materials. Very special metal alloys (such as niobium-tin and niobium-titanium), when cooled to extremely cold temperatures (approximately -269°C), will conduct electricity without any thermal resistance (loss of energy due to the dissipation of heat). These materials are called "superconductors". So, if there is a continuous loop of superconducting wire, cooled to the correct temperature, and charged with a certain amount of electric current, the current will flow indefinitely and generate a stable, persistent magnetic field. One popular application of superconducting magnets is seen in hospitals and clinics in a technique known as Magnetic Resonance Imaging, or MRI. These machines allow physicians to get very good photographs of soft tissue in the body and diagnose potential illnesses or injuries and treat them appropriately.