Final answer:
A parasitoid always kills its host and usually has a free-living adult stage, whereas a parasite typically does not kill its host, maintaining a longer-term relationship to ensure survival and spread.
Step-by-step explanation:
The difference between a parasitoid and a parasite is that a parasitoid always kills its hosts while parasites usually do not kill their hosts. Parasitoids and parasites can both live inside or on the body of their hosts; however, parasitoids typically have a free-living adult stage and an immature stage that is parasitic and eventually lethal to the host. Conversely, parasites tend to have a longer-term relationship with their hosts, draining resources but often keeping them alive to ensure continued survival and spread of the parasite.