The absolute refractory period refers to the phase during which a neuron cannot fire another action potential, regardless of the strength of the stimulus. This period occurs immediately after an action potential when voltage-gated sodium channels are inactivated.
More specifically, it starts at the peak of the action potential and continues until the membrane potential returns to a level near the resting potential, at which point sodium channels can begin to reset. The absolute refractory period is a critical component of the action potential and ensures that the impulse travels in one direction along the axon and that the neuron has time to recover.
In summary, the absolute refractory period cannot be elicited from the peak of the action potential until the neuron has reestablished its resting state and the sodium channels have reset, preventing any new action potential from occurring during that time.