Chemicals obtained from processing of Petroleum and Natural Gas are called Petrochemicals
Example
Methyl alchohol,ethyl alchohol,acetic acid,ethylene etc are obtained from processing of petroleum
Hydrogen gas is obtained from processing of Natural Gas
Uses of Petrochemicals
Polythene, Plastic Bags, Detergents are obtained from petrochemicals of Petroleum
Fertilizers like Urea are obtained from Hydrogen which is obtained from Natural Gas