The ancient Greeks and Chinese people find nature a kind of natural magnetization of stone, called "magnet." This stone can magically pick up small pieces of iron sheet, and after swinging freely always point in the same direction. Early sailors put this magnet as its earliest compass to identify the direction of the sea. After thousands of years of development, today has become a magnet strong material in our lives. By alloy synthesis of different materials to achieve the same effect with the magnet, but also can improve the magnetic force. In the 18th century there have been man-made magnets, but the manufacturing process is very stronger magnetic slowly until the 1920s to produce aluminum-nickel-cobalt (Alnico). Subsequently, the 1950s produced the ferrite (Ferrite), 70 years of manufacture rare earth magnets [Rare Earth magnet includes neodymium (NdFeB) and samarium cobalt (SmCo)]. Thus, magnetic science and technology has been rapid development of magnetic materials also makes the device more compact.
What is the magnetization (orientation) direction?
　　Most of the magnetic material can be magnetized to saturation in the same direction, this direction is called "a magnetization direction" (direction of orientation). No orientation direction of magnetic magnet (also called isotropic magnet) magnet orientation ratio (also called anisotropic magnet) is much weaker.
What is the standard of "poles" industry definition?
　　The definition of "Arctic" is freely rotating magnet after it's pointing to the Earth's North Pole Arctic. Similarly, also pointing to the earth magnet Antarctic South Pole. In the absence of labels how to identify magnet Arctic? Obviously just by eye is unable to distinguish. You can use the compass close to a magnet, a pointer pointing to the North Pole will point to the Earth's south pole magnets.