The throttle body plays a crucial role in the air intake process during engine operation, primarily controlling the amount of air entering the engine. It functions as a valve that regulates the airflow into the intake, ensuring the engine receives the proper air-fuel mixture for efficient combustion. Typically located between the intake manifold and the air intake filter, the throttle body adjusts the air restriction based on the input from the gas pedal. This adjustment helps the engine respond to varying driving conditions, such as acceleration, deceleration, and idle speeds, maintaining optimal performance.