Cephalopods are a group of animals that include squid, octopuses, and cuttlefish. They are usually found in the ocean, but a few cephalopods live in freshwater.
Squid are cephalopods, and they are the most common type of cephalopod.
Octopuses are cephalopods, but they are usually considered to be a different kind of animal.
Cuttlefish are cephalopods, but they are the smallest type of cephalopod.