Percocet is an opiate.
Percocet is neither an opiate nor a barbiturate. Percocet, which is the brand name for oxycodone, is what they call an OPIOID AGONIST. Opiates are derivatives of the opium poppy, and are naturally occurring in the plant. About the only two true opiates are morphine and codeine. Opioids are semi-synthetic or fully synthetic. Oxycodone is a semi-synthetic opioid agonist, along with hydrocodone (Vicodin, Lortab), hydromorphone (Dilaudid) and oxymorphone (Opana, Numorphan). Oxycodone is derived from thebaine, which is found in the opium poppy, and then chemically altered to create the medication. Most people use the terms opiate and opioid interchangeably, but there is a difference in what they are. There's a pretty good explanation of it on wikipedia.