* Idle Air Control Valve (IACV): This is a small valve that controls the amount of air entering the engine when it's idling (running at low speed). It's an electronically controlled valve that opens and closes to maintain the correct idle speed.
* Air Intake System: This is the entire system that brings air into the engine, including the air filter, intake manifold, throttle body, and various hoses and pipes. The IACV is just one small part of this larger system.
Think of it like this: the air intake system is the road, and the IACV is a traffic light controlling the flow of air at a specific point (idle).
