Oil markets explained

Big movements in the oil price have significant ramifications around the world. But just what makes the price move and how do the oil markets work? BBC News Online takes a closer look.

Crude oil, also known as petroleum, is the world's most actively traded commodity.

The largest markets are in London, New York and Singapore but crude oil and refined products - such as gasoline (petrol) and heating oil - are bought and sold all over the world.