Petroleum
In short
A naturally occurring liquid mixture of hydrocarbons found deep underground in geological formations. It is often called crude oil and serves as the primary raw material for fuels and plastics.
In plain words
It is a thick, dark liquid made from tiny sea creatures that died millions of years ago. Over a very long time, heat and pressure turned them into this fuel. We pump it out of the earth to make petrol and heating oil.
A simple example
When a refinery processes crude oil, it separates the mixture into different parts like diesel, jet fuel, and bitumen for roads.
Why it matters
It powers most of the world's transport and provides the building blocks for many everyday items. However, burning it releases carbon dioxide, which contributes to climate change.
Easy to mix up
Do not confuse petroleum with coal, which is a solid fossil fuel rather than a liquid.