The review aimed at updating and enriching the literature on the meaning, uses, origin, formation, exploration, processing and products of petroleum, major petroleum producing countries, octane number, the petrochemical industry and petroleum and the environment. It used the table research method to synergise dated and current reports. Petroleum or rock oil probably originated from underground organic matter or due to chemical reactions in the sky thousands of million years ago. It consists mainly of a mixture of gaseous, liquid and solid hydrocarbons which are broken into various products by fractional distillation during refining. From the medieval times, petroleum has been a source of energy and recently predominated the synthesis of organic compounds. Petroleum exploration and use have some environmental challenges.