Oil refining is the process of transforming crude oil into useful products like gasoline, diesel, and jet fuel. This involves separating the various components of crude oil through techniques such as distillation, where the oil is heated and its different parts are collected at various temperatures. After distillation, further processes like cracking and reforming are used to improve the quality and yield of the products. The refined oil can then be used in vehicles, heating, and even in the production of plastics and chemicals, making it a vital part of modern industry and daily life.