You must have come across plenty of magnets in your daily life, some stuck on your walls, refrigerator, some on the cupboards, or in toys. Magnets are found in many other appliances around the house like the telephone and radio. Even our planet earth is one giant ball of magnet, that attracts us all to the surface. Basically, there are two kinds of magnets: natural and man-made magnets. The natural magnets are rich in iron mineral and are called magnetite. Man-made magnets are made by processing metallic alloys to get the charges aligned. There are four main types of magnets which have been listed below: Magnets are those things which produce magnetic fields. They attract those objects which have opposite charges, and repel those that possess the same charge. That is why the saying goes as 'opposites attract'. The different types of magnets and their uses vary according to their composition and the field that they produce. The following paragraphs will explain all about these types in detail. The temporary magnets are those that act like permanent ones only when they are within a range of a strong magnetic field. As soon as they are removed from the field, they lose their magnetism. The objects that act as temporary magnets are paperclips, iron nails, etc. These type of magnets are used in telephones, electric motors, even in the production of electricity, etc. The electromagnets are the ones that are a tightly wound coil of wire. When current flows through the coil of wire (usually with an iron core), it acts like a permanent magnet. It is easy to change the strength and polarity of the magnetic field of these magnets. This can be done by changing the magnitude of the current flowing through the wire and changing the direction of electric charge. The uses of these variety include large cranes, lifting cables and rods during construction, television, computers, radios, video tapes, speakers, etc. The superconductors are the strongest amongst all the magnets. These magnets are also made of wire coils of special metal alloys without a metal core. These metal alloys become superconductors when they are cooled at very low temperatures. The superconductor magnet uses include Magnetic Resonance Imaging (MRI) machines, NMR equipment, mass spectrometers, magnetic separation process, and particle accelerators, etc. There are different types of magnets that vary in their size and shape. You could find tiny magnets that are used by the electronic industry and giant magnets that are used for cyclotron experiments. Even the strength of the magnets vary widely. Simple magnets that stick to your refrigerator have about one tenth of tesla strength. The U.S. Department of Energy's Berkeley Lab in 2001 built an electromagnet to bend the paths of high-speed atomic particles. The strength of this magnet was 14.7 tesla, the strongest in the world. It is a magnet that is U-shaped, which remains magnetized. The advantage of this magnet is that both its magnetic poles (N and S) are parallel to each other and facing the same direction. A magnet which has the shape of a rectangular bar is called a bar magnet. Its two ends depict the north and the south pole, respectively. This is a permanent magnet as it remains magnetized at all times. A magnet having small size and a rounded shape is called a round magnet. This usually has a hole at the center. It is used in holding small-sized objects such as a knob, earring, or a hook. Magnets have been used for over thousands of centuries by sailors to find their way around at seas. William Gilbert, in the early 1600s, began studying the magnets to prove that the earth too had magnetic properties and one could change magnetism by external methods. Since then, studies of magnets have helped in many useful inventions, which has come to the aid of mankind immensely.