ELI5: Explain Like I'm 5

Fuel oil

Fuel oil is a type of liquid that can be used to power things like heaters, boilers, and engines. It's made by mixing different types of oil and chemicals together until it forms a thick, black, gooey liquid. Just like how your parents mix different ingredients to make your favorite foods, people mix different types of oil to make fuel oil.

Fuel oil is usually stored in big tanks or barrels and can be delivered to homes and businesses by trucks. When it's used to power a heater, boiler, or engine, it's burned to create heat or energy. Think of how a campfire burns wood to make warmth - fuel oil does something similar, but it creates heat or energy rather than warmth and light.

Fuel oil also comes in different grades, which determine how clean it burns and how well it can power different types of equipment. Just like how different types of toys require different types of batteries, different types of equipment require different grades of fuel oil.