Engine:
Engines make a car run, by converting the heat energy produced by fuel combustion into mechanical work.
The most common type of engine is the straight or so-called inline engine. This is the most common engine layout in cars like the Toyota Supra MK4 and Nissan Skyline GT-R R34.
Next is the V-engine, an iconic engine used in many of our up-to-date supercars like the Porsche Carrera GT, Audi R8, and Dodge SRT Viper GTS, all these cars use the V-type V10 engine.
After that comes the flat or so-called boxer engine, which has a layout where the pistons are fixed horizontally, cars like the Porsche 911 GT3 and Toyota GT 86 use boxer engines.
These three are the most common types, now there are others like the H and W even O, and many more. The thing is, that in most of the types of engines, the pistons are aligned according to their name, like V, H, O, and W. There are also further modifications where there are W24 where 2 W12 engines are put together and many more.
How do each of these engines work:
How does internal combustion work: