Morphine is an Opiod Analgesic designed to relieve severe to moderate pain in patients and is a controlled substance.
Naloxone (or NarCan) is an Opiod Antagonist and is designed to reverse the effects of an overdose in opiates (i.e. Morphine). Most opiates have a longer half life (stay in your system longer) than Naloxone so administration may need to be repeated several times and the patient monitored for respiratory distress and o2 saturation as opiate overdoses can cause various dangerous symptoms which require supportive treatment alongside the Naloxone.