Cabin air filter:
A filtering system that meters out pollen, road dust and other particles before they can reach the passenger cabin.

Engine oil:
A substance that lubricates and cools the moving parts of the engine and reduces corrosion and the formation of rust.

Oil filter:
A cartridge-filled canister placed in an engine's lubricating system to strain dirt and abrasive materials out of the oil.

Air conditioning system:
The system of receiver/dryer, evaporator, condenser, compressor, refrigerant lines, controls and valves that allow for the controlled refrigeration of the air present in or entering a vehicle's interior.

Battery:
A box containing lead plates filled with a water and acid mixture that stores electricity generated by the alternator. It is the source of power for parts of the car that operate on electricity.

Body:
The outer panels that shroud the mechanical and electrical workings of a vehicle.

Brake master cylinder:
A device that stores brake fluid and hydraulically forces it through the brake lines to the brakes when the brake pedal is depressed.

Brake system:
A vehicle's stopping mechanism comprised of a pedal connected to a hydraulic master cylinder that can actuate clamping and/or expanding devices at all four wheels that slow or stop a vehicle's rolling motion. Components in a basic brake system are the master cylinder, calipers and/or wheel cylinders, linings or pads or shoes, rotors and/or drums.

Cabin air filter:
A filtering system that meters out pollen, road dust and other particles before they can reach the passenger cabin.

Clutch master cylinder:
In a manual-transmission vehicle with a hydraulically actuated clutch, a small-bore hydraulic cylinder mechanically connected to the clutch pedal that actuates a slave cylinder, which in turn actuates the clutch fork that disengages the clutch when the clutch pedal is depressed.

Coolant:
Also known as "antifreeze." A mixture of water and ethylene glycol that has both a higher boiling point and a lower freezing point than plain water.

Cooling system:
The system that stores and circulates coolant throughout (water cooled) engines to prevent overheating. Some vehicles have air-cooled engines in which high-speed airflow is sufficient to keep the engine cool.

Differential:
A set of gears that transfers the power of the rotating driveshaft to drive wheels in front and rear-wheel-drive vehicles. The differential also allows each of the opposing wheels to turn at a different speed when cornering.

Drive axles:
In a front-wheel drive vehicle or a rear-wheel drive vehicle with independent rear suspension, the short axles that connect the driven wheels with the driving force. Drive axles typically have CV (constant velocity)-joints on their ends.

Engine oil:
A substance that lubricates and cools the moving parts of the engine and reduces corrosion and the formation of rust.

Exhaust system:
A system of tubing that routes exhaust gases from the exhaust manifold to the rear of the car and into the air. The exhaust system includes catalytic converters and mufflers that help reduce air and noise pollution generated by an engine.

Fuel lines, hoses & connections:
The tubing and connections that carry fuel throughout a vehicle.

Hinges, locks & latches:
The devices that allow or prevent the opening of doors and hatches.

Lights & accessories:
Any source of illumination and any electrically operated convenience device.

Oil filter:
A cartridge-filled canister placed in an engine's lubricating system to strain dirt and abrasive materials out of the oil.

On-board diagnosis system:
A computer-controlled system that identifies malfunctioning or out-of-adjustment components under its control through the display of trouble codes. The presence of trouble codes is usually indicated by an intermittently or constantly lit "check engine " or "service engine soon" light.

Parking brake:
The mechanical brake connected by cables to either a ratcheting hand lever or foot pedal used to hold or apply a vehicle's rear and sometimes front brakes while left unattended or under conditions of hydraulic circuit failure. Sometimes referred to as the emergency brake.

Power steering:
A system that includes a power steering pump attached to the engine and driven by a belt, a pressure hose assembly, and a return line. A control valve is also incorporated somewhere in the hydraulic circuit.

Power steering fluid:
Hydraulic fluid used in a power steering system.

Road test:
The actual driving of a vehicle under real-world conditions in order to find any abnormalities in its operation.

Seat belts:
The latching straps in a vehicle designed to minimize the risk of serious injury to the user in the event of an accident when used as suggested.

Service reminder light:
A light that indicates that general vehicle maintenance is needed or that a specific service is required.

Steering & suspension:
A vehicle's steering is the collection of components that enable the operator to direct a vehicle in a desired direction. Suspension is the assemblage of joints, links and other components between a vehicle and its wheels.

Supplemental Restraint System:
System composed of a safety devices that do not require any action on the part of the occupants to be effective, and its controls and sensors.

Transmission:
The part of a vehicle's power train that transmits power from the engine to the remainder of the power train trough a series of gear ratios.

Warning lights:
Lights on a vehicle's instrument panel that notify the operator of a malfunction or a circumstance needing attention.

Wheels & tires:
A circular frame of hard material that may be solid or partly solid, is capable of turning on an axle, and holds the rubber cushion that contains compressed air.

Windshield wipers & washer:
Motorized mechanical arms with rubber inserts used to wipe the windshield or back glass. A small pump and reservoir that can direct a jet of cleaning solution at the windshield or back glass.