Fuel oil is any of various fractions obtained from the distillation of petroleum (crude oil). Such oils include distillates (the lighter fractions) and residues (the heavier fractions). Fuel oils include heavy fuel oil (bunker fuel), marine fuel oil (MFO), furnace oil (FO), gas oil (gasoil), heating oils (such as home heating oil), diesel fuel and others.

Bunker fuel is the fuel oil gas conveyed to boats of all expresses that are occupied with a universal route, which may happen by means of the ocean, on inland lakes and conduits, and in beachfront waters. The two noteworthy fortifications energize utilized in the marine business are distillates and leftover fuel oils. Marine distillates are isolated into marine gas oil (MGO) and marine diesel oil (MDO). Marine gas oils are utilized in little, exceptionally evaluated diesel motors, which are found in numerous sorts of boats. Lingering fuel oil, otherwise called substantial fuel oil (HFO), is the most noteworthy consistency oil fuel.