World oil reserves refer to the total amount of crude oil that is estimated to exist in the world. This term can be interchanged with different synonyms such as global petroleum stock, international oil resources, and worldwide fossil fuel deposits. These synonyms all indicate the same idea that the world has a limited amount of oil resources that are available for extraction. Due to the increasing demand for energy resources, the world's oil reserves are becoming more and more important, and it is essential that we find alternative and sustainable energy sources to ensure long-term energy security for the future.