How does an action potential differ from simple depolarization

A simple depolarization can be defined as any change that occurs in a neuron that results to it being more positive than resting potential, but an action potential happens only when the simple depolarization reaches the threshold or optimum level.

Explanation:

A simple depolarization can be defined as any change that occurs in a neuron that results to it being more positive than resting potential, but an action potential happens only when the simple depolarization reaches the threshold or optimum level.