What is the relationship between natural gas and petroleum?

Natural gas has or had something to do with oil while petroleum is rock oil.

The natural gas and petroleum both are present at the bottom of the earth's surface and they both are the sources of fuel.

Explanation:

The natural gas petroleum are non sustainable sources of energy.

Natural gas and petroleum are fossil fuels. Both natural gas and petroleum are present at the bottom of the surface of the earth.

Both are formed from the dead parts of the parts and animals. Natural gas and petroleum are used for the heating purposes.

Natural gas and petroleum are used for transportation.