Thousands of years ago it was accidentally discovered that pieces of certain grayish-black rock would cling to the iron point of a spear. This mineral rock was called "lodestone" meaning "leading stone" and consisted of a compound of iron & oxygen. Lodestone is the earth's only natural magnet.
The Greeks knew of lodestone as early as 2500 years ago. The name "magnet" refers to the Greek province of "magnesia" where natural magnets were especially plentiful.
Magnets today are man-made. The most common magnets are either alnico or ceramic magnets. Alnico magnets look like steel, but are actually a mixture, or alloy, of aluminum, nickel, and cobalt. Ceramic magnets are usually made from strontium ferrite.
Magnets will attract any object which is ferrous, i.e. containing iron. A simple magnet has two poles- the north-seeking pole and the south-seeking pole. The end of the magnet pointing toward the geographical North Pole of the earth is the north-seeking pole.