A glow engine is like a little car engine, but smaller and fancier. It runs on a special type of fuel that is made up of alcohol, nitro-methane, and a special oil. When you want to start it, you have to use a little battery-powered glow plug. This glow plug gets hot and ignites the fuel mixture in the engine, which makes the engine start running. Once it's running, it gets more air from a little fan, which helps the engine run faster and hotter. The hotter the engine gets, the better it runs. You have to be careful with a glow engine though, because it can get really hot and burn you. That's why you should always have an adult around when you're working with it.