Petrochemistry and refining are branches of the oil and gas industry that focus on processing crude oil into raw materials and products such as fuels, chemicals and plastics. Refineries refine and separate crude oil into different products such as petrol, diesel and other fuels. Petrochemistry focuses on producing raw materials for the chemicals industry, such as ethylene and propylene. These are used to make a wide range of products from plastics to textiles, paints and medicines.