The apex is the true center of the corner where the car changes direction. At some tracks this can be before the visual center of the turn. Braking pressures are ideally at zero before entering this zone and the car is allowed to roll through the middle. Steering input is usually at its maximum point at the apex. The car takes a set and changes direction at the apex.
Acceleration begins after the car takes a set.
The acceleration zone is the area just past the middle of the turn where the driver gets down harder on the accelerator. A good roll through the middle and a strong ability to get the throttle down, sets the car up for a good turn exit. Steering input reduces as the car travels through this zone. The exit of the turn is the area just past the acceleration zone where the car makes the final approach to the straightaway. Steering input is reduced to zero and throttle pressure is increased to maximum as the car travels off the turn.