Modafinil is a prescription medication designed to promote wakefulness and combat excessive fatigue caused by conditions such as narcolepsy, obstructive sleep apnea, and shift work sleep disorder. It works by stimulating certain neurotransmitters in the brain that regulate alertness, helping individuals maintain focus and energy throughout the day. Unlike traditional stimulants, modafinil provides a more controlled and sustained effect, making it a preferred choice for patients who need prolonged mental clarity without jitteriness or sudden energy crashes.