Most cars on the road today are powered by an internal combustion engine. The job of the Engine is to turn fuel (usually gasoline or diesel) and air into energy that powers the vehicle, turning the wheels and moving the car. The engine is started by the driver by activating the electrical system which uses the power stored in the vehicle's battery to turn an electric motor which begins the rotation of the engine. After the engine has started turning the Intake valves will open allowing air and fuel into the combustion chambers. the air/fuel mixture is drawn into the combustion chamber by vacuum as it expands. The intake valves then close and the combustion chamber begins to shrink compressing the air/fuel mixture in the process. Once the mixture is compressed fully spark is delivered to the combustion chamber igniting the mixture and rapidly forcing the chamber to expand. The job of the electric motor (starter) is now complete as the engine's exhaust valves open to release the pressure and unburnt gasses and the next chamber begins the process to continue the rotation of the engine.

The job of the fuel system is to take fuel (usually gasoline or diesel) from the vehicle's tank via the vehicle's fuel pump powered by the electrical system through the fuel lines and filters, to the fuel rail to reach the injectors which deliver the fuel to the combustion chamber. Excess fuel pumped up to the rail is then bled off past the regulator and fed back to the tank for recirculation.

The charging and electrical system are made up of the battery, alternator, and starter, as well as various other components in the vehicle from your headlights to the window switches and motors, and even components that control the timing of when to deliver fuel and spark to the engine. the main few things to grasp here though are that the car's battery stores power while the vehicle is off so that the starter motor can be engaged to begin the rotation of the engine and the alternator powers the electrical components of the car after the engine is running as well as sending power back to the battery to maintain its charge.

The electrical system of an automobile is quite advanced in modern days so much so that many cars meet the end of their lives not because of internal wear or damage to physical parts like the engine, transmission, or the body & suspension but because of electrical failure to one of the hundreds of components of the electrical system that prevent the vehicle from operating as it was intended.

(this section will eventually include a list of many electrical parts as well as a description of what they are and how they function)

The Drivetrain is the parts (such as the universal joint and the driveshaft) that connect the transmission with the driving axles of an automobile

Engine intake fans draw fresh, clean air into a space, while exhaust fans move warm, stale air (or air contaminated by manufacturing or production practices) out.

The cooling system is composed of various parts: the radiator, pressure cap, fan, pump, thermostat, hoses and overflow tank.

Braking system means the components required to stop a motor vehicle including the braking pedal, master cylinder, con- necting hoses, lines, fluids, linkage, drums, shoes, rotors, pads, calipers and parking brake.

Suspension is the system of tires, tire air, springs, shock absorbers and linkages that connect a vehicle to its wheels and allows relative motion between the two. Suspension systems must support both road holding/handling and ride quality, which are at odds with each other. 

A vehicle frame, also historically known as its chassis, is the main supporting structure of a motor vehicle to which all other components are attached, comparable to the skeleton of an organism.