MAGNETS 
Types of magnets
Ring magnet
Horseshoe magnet
Button/Disc magnet
Bar magnet
Cylindrical magnet
Strengths of magnets
The amount of pins or coins it holds.
Bar magnets: 4-5 pins
Button magnet/disc magnet: 2 pins
Cylindrical magnet: 3 pins
Ring magnet: 2 pins
Horseshoe magnet: 3 pins
Properties of a magnet
Opposite poles of two magnets attract.
Like poles of two magnets repel.
Poles always exist in pairs. They cannot be separated.
If a magnet is suspended freely in mid-air with a thread, it will align it's self in the north-south direction.
Magnets have two poles the north (N) pole and the south (S) pole.
Magnets attract only nickel, cobalt and iron. Magnets also attract electromagnets and magnets that have an alloy.
Fun Facts
Legend says that a shepherd from Greece named Magnes was the first to discover these magnetic rocks when the iron tip of his staff was pulled towards a stone as he passed over it. Subsequently, these rocks were named lodestones, and went on to be called magnetite, possibly after Magnes himself.
In the past, lodestone was used by sailors as an aid to navigation. They had discovered that when they suspended a piece of magnetite by a thread, it always pointed in a north-south direction. This is now called the compass.
The Earth is like one big bar magnet. It has a magnetic north and a magnetic south, which is what the needle on a compass points to. The geographical north pole is the magnetic south pole and the geographical south pole is a magnetic north pole.
Let me tell you why, do you remember one property of the magnet the one which is that opposite poles of two magnets attract so that means that the magnetic north pole and the geographical south pole attract and vice versa... Now do you understand?