Magnets

Magnets are quite uncommon but also very common. If you went about your daily life, you probably wouldn't notice a magnet unless you placed it next to a ferromagnetic metal (metals that magnets can attract).

Magnets are used everywhere. A few examples would be telephones, computers, some cranes, refrigerators, and televisions.

The earth itself is a big magnet. This is the reason why compasses even work. Every compass needle is actually a very light magnet. That is also the reason the North Pole is actually the magnetic South Pole. This is because opposites attract and thus the north pointer on a compass will always point to the magnetic south pole.

Not all planets have magnetic fields. Compared to the Earth, the four gas giants have extremely strong magnetic fields, Mercury has an extremely weak field, and Venus and Mars have almost no measurable fields.

You can imagine (emphasis on imagine) a magnet as a piece of metal containing lots of little magnets all facing the same direction. Thus you can cut a magnet and it will still be magnetic, just weaker. If you drop a magnet, some of those little magnets won't face the same direction as the rest anymore and thus it will weaken. In the same sense, you can create a magnet with any ferromagnetic metal. All you need to do is rub a magnet across it's surface in the same direction multiple times and Voila you created a temporary magnet. This is because ferromagnetic metals also contain little magnets just that they are normally scrambled. By running a magnet across it, you can orient those magnets in one direction and magnetize it.

Farmers make their cows swallow a magnet to prevent themselves from self harm. Cows just eat whatever they want and this also includes wires and screws that may be lying around. Without the magnet, the wires and screws would pass through their stomachs and destroy their organs. It's almost like how vaccines works. You make a cow eat a metal to protect it from other metals.