1. Squid head structure is different, squid head on both sides of a small piece of fin like things to maintain balance, but Octopus does not.

2. Squid head to body ratio is different, squid head to body ratio is much larger than octopus, and more slender.

3. Different body structure, squid has a small amount of cartilage in its body, so it has some shape than octopus, in contrast, it has a relatively fixed shape.

Squid, also known as squid and squid, is a kind of animal of Mollusca phylum Cephalopoda, Coleoptera, Decapoda, Siphonophora, and eye opening suborder. It has a conical body, pale body, pale brown spots, large head, 10 palpable feet in front, and triangular fin at the tail, which often swim in groups in the ocean about 20 meters deep.

Octopus, also known as octopus, is a mollusk that evolved from cephalopod mollusks. The body is generally very small, eight tentacles are thin and long, so it is also known as "octopus".