Percocet is a combination medication that contains oxycodone, an opioid pain reliever, and acetaminophen, a non-opioid pain reliever and fever reducer. It is used to manage moderate to severe pain. Oxycodone works by binding to opioid receptors in the brain and spinal cord to reduce the perception of pain, while acetaminophen helps enhance the pain-relieving effects of oxycodone.