Oil was first formed when tiny plants and animals died under the sea. when they died, they sank to the ocean floor. Most of them turned to rock, but for some of them, the weight of the water and the heat and chemicals turned them into oil and gas.
Oil companies need to drill at the cap rock to get oil. Sometimes, the oil doesn't pump, and they inject water or gas to make pressure. When the crude oil reaches the surface, they have to refine the oil to make it into things like gasoline and asphalt.
Oil can be used to make things like gasoline, plastics, wax for candles, and other things as well.
The unequal distribution of oil has cause something known as the oil wars. These wars consisted of companies fighting for control over oil.
To go into more detail, Kuwait has 7% of the world's oil reserves, although Saudi Arabia could fit over 120 Kuwait's inside of it. This unequal distribution has been the cause of many wars between countries fighting over the oil.
We could stop these conflicts by finding a way to make sure every continent gets and equal - or close to equal- amount of oil in their reserves.