Crude oil is a mixture of hydrocarbons that exists as a liquid in underground geologic formations and remains a liquid when brought to the surface. Petroleum products are produced from the processing of crude oil and other liquids at petroleum refineries, from the extraction of liquid hydrocarbons at natural gas processing plants, and from the production of finished petroleum products at blending facilities. Petroleum is a broad category that includes both crude oil and petroleum products. The terms oil and petroleum are sometimes used interchangeably.

Factors on the demand-side include weather (temperatures), economic conditions, and petroleum prices. Cold weather (low temperatures) increases demand for heating, while hot weather (high temperatures) increases demand for cooling, which increases natural gas demand by electric power plants. Economic conditions influence demand for natural gas, especially by manufacturers. Demand may be moderated by petroleum fuel prices, which may be an economical substitute for natural gas for power generators, manufacturers, and large building owners. Higher demand tends to lead to higher prices, while lower demand can lead to lower prices. Increases and decreases in prices tend to reduce or increase demand.

Kerosene is combustible, burns strongly, and offers a strong amount of heat. By contrast, propane is cleaner burning and can easily be found at most gas stations and grocery stores. It's also much cheaper than kerosene.

The fluid was an excellent lamp fuel, and he named it kerosene, meaning wax-oil. Although kerosene is still widely used as a heating fuel, it can also be used to lubricate watch cogs, bicycles and vehicle engines.