Since electricity was invented, it has been incorporated into nearly every aspect of human life. Every building is lit up like a Christmas tree by electric lights, and the technological gadgets that our society adores are all enabled by electricity. Even those gadgets run by batteries are a better deal if they can be re-charged with electricity. These are just two examples amongst a plethora of electric applications, which is why it should come as no surprise that electromagnets, which are magnets that only work when they have an electric current running through them, are popular. However, the electricity free magnets, known as permanent magnets, are equally as popular because they are a less expensive investment and also require less set up and maintenance when being used in an industrial setting, as many magnets are.
Permanent magnets maintain a magnetic field always, a state that never goes away unless the magnet itself is destroyed. Sometimes enough dirt or corrosion build-up can also decrease the magnetic field to the point where it no longer holds things together. These are the types of magnets that we civilians know as refrigerator magnets, and they are also used in much larger configurations holding together heavy duty industrial systems. For example, permanent magnets can be used within computer data processing without using any of the electricity that is required to activate other parts of the system. These particular types of magnets are usually rare earth magnets, because they have the strongest magnetic qualities. There are also applications in between the two polar examples of simple and complex, the refrigerator magnets and the magnetic assemblies used in computer data processing. Alnico magnets and ceramic magnets are other types of permanent magnets attached to moving cranes within factories where metals are fabricated, used to collect and organize the metal scrap after processing.